Antibody to TNF receptor-like molecules

ABSTRACT

Novel MK61 polypeptides and nucleic acid molecules encoding the same. The invention also provides vectors, host cells, selective binding agents, and methods for producing MK61 polypeptides. Also provided for are methods for the treatment, diagnosis, amelioration, or prevention of diseases with MK61 polypeptides.

The present application is a continuation application of U.S. patentapplication Ser. No. 09/948,018, now issued U.S. Pat. No. 7,153,669,which was filed Sep. 5, 2001, which in turn claims benefit under 35U.S.C. § 119 of U.S. Application Ser. No. 60/230,191, which was filedSep. 5, 2000, which is incorporated herein by reference in its entirety.

FIELD OF THE INVENTION

The present invention relates to novel TNF receptor. (TNFr)-likepolypeptides and nucleic acid molecules encoding the same, termed “MK61”herein.

The invention also relates to vectors, host cells, pharmaceuticalcompositions, selective binding agents and methods for producing MK61polypeptides. Also provided for are methods for the diagnosis,treatment, amelioration, and/or prevention of diseases associated withMK61 polypeptides.

BACKGROUND OF THE INVENTION

Technical advances in identification, cloning, expression andmanipulation of nucleic acid molecules and deciphering of the humangenome have greatly accelerated discovery of novel therapeutics basedupon deciphering of the human genome. Rapid nucleic acid sequencingtechniques can now generate sequence information at unprecedented ratesand, coupled with computational analyses, allow the assembly ofoverlapping sequences into the partial and entire genomes as well asidentification of polypeptide-encoding regions. A comparison of apredicted amino acid sequence against a database compilation of knownamino acid sequences allows one to determine the extent of homology topreviously identified sequences and/or structural landmarks. The cloningand expression of a polypeptide-encoding region of a nucleic acidmolecule provides a polypeptide product for structural and functionalanalyses. The manipulation of nucleic acid molecules and encodedpolypeptides to create variant and derivatives thereof may conferadvantageous properties on a product for use as a therapeutic.

In spite of significant technical advances in genome research over thepast decade, the potential for development of novel therapeutics basedon the human genome is still largely unrealized. Many genes encodingpotentially beneficial polypeptide therapeutics or those encodingpolypeptides, which may act as “targets” for therapeutic molecules, havestill not been identified.

Accordingly, it is an object of the invention to identify novelpolypeptides, and nucleic acid molecules encoding the same, which havediagnostic or therapeutic benefit.

After years of study in necrosis of tumors, tumor necrosis factors(TNFs) α and β were finally cloned in 1984. The ensuing years witnessedthe emergence of a superfamily of TNF cytokines, including fas ligand(FasL), CD27 ligand (CD27L), CD30 ligand (CD30L), CD40 ligand (CD40L),TNF-related apoptosis-inducing ligand (TRAIL, also designated AGP-1),osteoprotegerin binding protein (OPG-BP or OPG ligand), 4-1BB ligand,LIGHT, APRIL, and TALL-1. Smith et al. (1994), Cell, 76: 959-962; Laceyet al. (1998), Cell, 93: 165-176; Chichepotiche et al. (1997), J. Biol.Chem., 272: 32401-32410; Mauri et al. (1998), Immunity, 8: 21-30; Hahneet al. (1998), J. Exp. Med., 188: 1185-90; Shu et al. (1999), J.Leukocyte Biology, 65: 680-3. This family is unified by its structure,particularly at the C-terminus. In addition, most members known to dateare expressed in immune compartments, although some members are alsoexpressed in other tissues or organs, as well. Smith et al. (1994), Cell76: 959-62. All ligand members, with the exception of LT-α, are type IItransmembrane proteins, characterized by a conserved 150 amino acidregion within C-terminal extracellular domain. Though restricted to only20-25% identity, the conserved 150 amino acid domain folds into acharacteristic β-pleated sheet sandwich and trimerizes. This conservedregion can be proteolyticaly released, thus generating a solublefunctional form. Banner et al. (1993), Cell, 73: 431-445.

Many members within this ligand family are expressed in lymphoidenriched tissues and play important roles in the immune systemdevelopment and modulation. Smith et al. (1994). For example, TNFα ismainly synthesized by macrophages and is an important mediator forinflammatory responses and immune defenses. Tracey & Cerami (1994),Annu. Rev. Med., 45: 491-503. Fas-L, predominantly expressed inactivated T cell, modulates TCR-mediated apoptosis of thymocyts. Nagataet al. (1995) Immunology Today, 16:39-43; Castrim et al. (1996),Immunity, 5:617-27. CD40L, also expressed by activated T cells, providesan essential signal for B cell survival, proliferation andimmunoglobulin isotype switching. Noelle (1996), Immunity, 4: 415-9.

The cognate receptors for most of the TNF ligand family members havebeen identified. These receptors share characteristic multiplecysteine-rich repeats within their extracellular domains, and do notpossess catalytic motifs within cytoplasmic regions. Smith et al.(1994). Two subgroups of TNFR homologues: Fas, TNFR1, DR3, DR4, DR5, andDR6 contains intracellular death domain which bind TRAD or FADD. Thisleads to activation of caspase 8 and apoptosis. Locksley et al. (2001)Cell 104: 487-501. However, signaling through death-receptors can alsobe required for proliferation of hepatocytes and T cells. Strasser etal., (1999) Intl. J. Biochem. Cell Biol. 31: 533-537, Yamada et al.(1997), Proc. Natl. Acad. Of Sci. U.S.A, 94: 1441-6. The other groupincluding TNFR2, CD40, or CD30 bind TNF-Receptor Associated Factors(TRAFs), molecular adapters that couple these surface receptors todownstream signaling cascades. This leads to activation of JNK and NFKBwhich can promote cell growth and survival. These proteins thereforeplay critical roles in morphogenesis, the control of apoptosis,differentiation, or proliferation. TNF/TNFR superfamily proteins are nowextensively studied as targets for therapies against many human diseasessuch as atherosclerosis, allograft rejection, arthritis, and cancer.Locksley et al. (2001), Williams et al. (2000), Ann. Rhem. Dis. 59:i75-80.

In addition to the membrane associated receptor molecules describedabove, a number the receptors belonging to the TNF-receptor supergenefamily exist as soluble ligand binding proteins. Many of the solubleforms of the transmembrane receptors were subsequently identified ascontaining only the extracellular ligand binding domain(s) of thereceptors. For example, a soluble form of TNF receptor has been found inurine and serum (see U.S. Pat. No. 5,843,789 and Nophar et al., EMBO J.,9(10):3269-3278, 1990), and have been shown to arise by proteolyticcleavage of cell surface TNF-receptors (Wallach et al., Agents ActionsSuppl., 35:51-57, 1991). These soluble forms of receptor molecules havebeen implicated in the modulation of TNF activity by not onlyinterfering with TNF binding to its receptor, but also by stabilizingthe TNF structure and preserving its activity, thus prolonging some ofits effects (Aderka et al, Cytokine & Growth Factor Reviews,7(3):231-240, 1996).

Members of the tumor necrosis factor superfamilies of ligands andcell-surface receptors regulate immune function and most TNF/TNFRsuperfamily proteins, such as FASL/FAS, CD40L/CD40, TNF/TNFR, orLTβ/LTβR to name a few, are expressed in the immune system, where thecoordinate immune cell homeostasis, activation induced cell death, Tcells priming, functions and survival of dendritic cells, or theformation of germinal centers and lymphoid organs such as Peyer'spatches and lymph nodes. Fu et al. (1999), Ann. Rev. Immunol. 17:399-433, Grewal et al. (1998), Ann. Rev. Immunol. 166: 111-135.Recently, novel members of this large families have been identified thathave critical functions in immunity and couple lymphoid cells with otherorgan systems such as bone morphogenesis and mammary gland formation inpregnancy.

Because of the crucial role that members of the TNF family of ligandsand their receptors (membrane-associated and soluble) play in theimmunological system and in a variety of disease processes, a needexists to identify and characterize novel members of these families, foruse to improve diagnosis and therapy.

SUMMARY OF THE INVENTION

The present invention relates to novel MK61 nucleic acid molecules andencoded polypeptides.

In accordance with the invention, a number of human MK61 isoforms aredescribed herein: “hMK61T1”, “hMK61T2”, “hMK61T3”, “hMK61T4”, “hMK61T5”,and “hMK61T6”. Additionally, a mouse isoform (“mMK61”) and an Fc-fusionpolypeptide thereof (“mMK61-Fc” and “hMK61-Fc”) are described herein.

The invention provides for an isolated nucleic acid molecule comprisinga nucleotide sequence selected from the group consisting of:

(a) the nucleotide sequence as set forth in SEQ ID NO:1, SEQ ID NO:3,SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13, orSEQ ID NO:15;

(b) a nucleotide sequence encoding the polypeptide as set forth in SEQID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16;

(c) a nucleotide sequence which hybridizes under moderately or highlystringent conditions to the complement of (a) or (b), wherein theencoded polypeptide has an activity of the polypeptide as set forth inSEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16; and

(d) a nucleotide sequence complementary to any of (a) through (c).

The invention also provides for an isolated nucleic acid moleculecomprising a nucleotide sequence selected from the group consisting of:

(a) a nucleotide sequence encoding a polypeptide that is at least about70, 75, 80, 85, 90, 95, 96, 97, 98 or 99 percent identical to thepolypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, OR SEQ ID NO:16,wherein the encoded polypeptide has an activity of the polypeptide asset forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(b) a nucleotide sequence encoding an allelic variant or splice variantof the nucleotide sequence as set forth in SEQ ID NO:1, SEQ ID NO:3, SEQID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13, or SEQ IDNO:15, wherein the encoded polypeptide has an activity of thepolypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(c) a nucleotide sequence of SEQ ID NO:1, (a), or (b) encoding apolypeptide fragment of at least about 25 amino acid residues, whereinthe polypeptide has an activity of the polypeptide as set forth in SEQID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16;

(d) a nucleotide sequence encoding a polypeptide that has at least oneamino acid substitution and/or deletion of the amino sequence set forthin any of SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16, wherein the encodedpolypeptide has an activity of the polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16;

(e) a nucleotide sequence of SEQ ID NO:1, or (a)-(d) comprising afragment of at least about 16 nucleotides;

(f) a nucleotide sequence which hybridizes under moderately or highlystringent conditions to the complement of any of (a)-(e), wherein theencoded polypeptide has an activity of the polypeptide as set forth inSEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, OR SEQ ID NO:16; and

(g) a nucleotide sequence complementary to any of (a)-(e).

The invention further provides for an isolated nucleic acid moleculecomprising a nucleotide sequence selected from the group consisting of:

(a) a nucleotide sequence encoding a polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16 with at least one conservative amino acidsubstitution, wherein the encoded polypeptide has an activity of thepolypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(b) a nucleotide sequence encoding a polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16 with at least one amino acid insertion,wherein the encoded polypeptide has an activity of the polypeptide asset forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(c) a nucleotide sequence encoding a polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16 with at least one amino acid deletion,wherein the encoded polypeptide has an activity of the polypeptide asset forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(d) a nucleotide sequence encoding a polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16 which has a C- and/or N-terminaltruncation, wherein the encoded polypeptide has an activity of thepolypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(e) a nucleotide sequence encoding a polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16 with at least one modification selectedfrom the group consisting of amino acid substitutions, amino acidinsertions, amino acid deletions, C-terminal truncation, and N-terminaltruncation, wherein the encoded polypeptide has an activity of thepolypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(f) a nucleotide sequence of (a)-(e) comprising a fragment of at leastabout 16 nucleotides;

(g) a nucleotide sequence which hybridizes under moderately or highlystringent conditions to the complement of any of (a)-(f), wherein theencoded polypeptide has an activity of the polypeptide as set forth inSEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16; and

(h) a nucleotide sequence complementary to any of (a)-(e).

The invention also provides for an expression vector comprising theisolated nucleic acid molecules set forth herein; recombinant host cells(eukaryotic and/or prokaryotic) that comprise the vector; the processfor producing a h2520 polypeptide comprising culturing the host cellunder suitable conditions to express the polypeptide and optionallyisolating the polypeptide from the culture; and the isolated polypeptideproduced by this process. The nucleic acid molecule used in this processmay also comprise promoter DNA other than the promoter DNA for thenative MK61 polypeptide operatively linked to the nucleotide sequenceencoding the MK61 polypeptide.

The invention also provides for a nucleic acid molecule as described inthe previous paragraphs wherein the percent identity is determined usinga computer program selected from the group consisting of GAP, BLASTP,BLASTN, FASTA, BLASTA, BLASTX, BestFit, and the Smith-Watermanalgorithm.

The present invention provides a process for identifying candidateinhibitors and/or stimulators of MK61 polypeptide activity or productioncomprising exposing a host cell to the candidate inhibitors and/orstimulators, measuring MK61 polypeptide activity or production in thehost cell, and comparing this activity with control cells (i.e., cellsnot exposed to the candidate inhibitor and/or stimulator). In a relatedaspect, the invention provides for the inhibitors and/or stimulatorsidentified by any of the preceding methods.

The invention also provides for an isolated polypeptide comprising theamino acid sequence set forth in SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO:6, SEQ ID NO: 8, SEQ ID NO: 10, SEQ ID No: 12, SEQ ID NO: 14 or SEQ. IDNO: 16.

The invention also provides for an isolated polypeptide comprising theamino acid sequence selected from the group consisting of:

(a) the mature amino acid sequence set forth in SEQ ID NO:2, SEQ IDNO:4, SEQ ID NO:6, SEQ ID. NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16, and optionally further comprising anamino-terminal methionine;

(b) an amino acid sequence for an ortholog of SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16, wherein the polypeptide has an activity of the polypeptideas set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(c) an amino acid sequence exhibits at least about 70, 75, 80, 85, 90,95, 96, 97, 98 or 99 percent identity to the amino acid sequence of SEQID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16, wherein the polypeptide has anactivity of the polypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16 as determined using a computer program selected from thegroup consisting of GAP, BLASTP, BLASTN, FASTA, BLASTA, BLASTX, BestFitand the Smith-Waterman algorithm.;

(d) a fragment of the amino acid sequence set forth in SEQ ID NO:2, SEQID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16 comprising at least about 25 amino acid residues,wherein the polypeptide has an activity of the polypeptide as set forthin SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQID NO:12, SEQ ID NO:14, or SEQ ID NO:16; and

(e) an amino acid sequence for an allelic variant or splice variant ofeither the amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16, or at least one of (a)-(c) wherein the polypeptide has anactivity of the polypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16.

The invention further provides for an isolated polypeptide comprisingthe amino acid sequence selected from the group consisting of:

(a) the amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16, with at least one conservative amino acid substitution,wherein the polypeptide has an activity of the polypeptide as set forthin SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQID NO:12, SEQ ID NO:14, or SEQ ID NO:16;

(b) the amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16, with at least one amino acid insertion, wherein thepolypeptide has an activity of the polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16;

(c) the amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16, with at least one amino acid deletion, wherein thepolypeptide has an activity of the polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16;

(d) the amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16 which has a C- and/or N-terminal truncation, wherein thepolypeptide has an activity of the polypeptide as set forth in SEQ IDNO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12,SEQ ID NO:14, or SEQ ID NO:16; and

(e) the amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4,SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, orSEQ ID NO:16, with at least one modification selected from the groupconsisting of amino acid substitutions, amino acid insertions, aminoacid deletions, C-terminal truncation, and N-terminal truncation,wherein the polypeptide has an activity of the polypeptide as set forthin SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQID NO:12, SEQ ID NO:14, or SEQ ID NO:16.

Analogs of MK61 are provided for in the present invention which resultfrom conservative and non-conservative amino acid substitutions of theMK61 polypeptide of SEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ IDNO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16. Suchanalogs include a MK61 polypeptide wherein the amino acid correspondingto position 38, 39 or 51 of SEQ ID NOS: 2, 4, 6, 8, 10 or 12 iscysteine, serine or alanine; a MK61 polypeptide wherein the amino acidcorresponding to position 60 or 76 of SEQ ID NOS: 2 or 6 is cysteine,serine or alanine a MK61 polypeptide wherein the amino acidcorresponding to position 41, 42, 54, 63 or 79 of SEQ ID NOS: 14 or 16is cysteine, serine or alanine; a MK61 polypeptide wherein the aminoacid corresponding to position 171 or 172 of SEQ ID NO: 2 is leucine,norleucine, valine, methionine, alanine or phenylalanine; a MK61polypeptide wherein the amino acid corresponding to position 178 or 180of SEQ ID NOS: 14 or 16 is leucine, norleucine, valine, methionine,alanine or phenylalanine; a MK61 polypeptide wherein the amino acidcorresponding to position 141 of SEQ ID NOS: 14 or 16 is glycine,proline or alanine.

The invention also provides methods of inhibiting MK61 receptor and/orligand activity in a mammal, which comprises administering at least onepolypeptide set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ IDNO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16.

Also provided are fusion polypeptides comprising the amino acidsequences of (a)-(e) above. In addition, the invention encompassesfusion polypeptides comprising the amino acid sequences of SEQ ID NO:16, SEQ ID NO: 36 and SEQ ID NO: 39.

The present invention also provides for an expression vector comprisingthe isolated nucleic acid molecules as set forth herein, recombinanthost cells comprising recombinant nucleic acid molecules as set forthherein, and a method of producing an MK61 polypeptide comprisingculturing the host cells and optionally isolating the polypeptide soproduced.

A transgenic non-human animal comprising a nucleic acid moleculeencoding an MK61 polypeptide is also encompassed by the invention. TheMK61 nucleic acid molecules are introduced into the animal in a mannerthat allows expression and increased levels of the MK61 polypeptide,which may include increased circulating levels. The transgenic non-humananimal is preferably a mammal.

Also provided are derivatives of the MK61 polypeptides of the presentinvention.

The present invention further provides for an antibody or fragmentthereof that specifically binds an MK61 polypeptide as set forth herein.This antibody can be polyclonal or monoclonal, and can be produced byimmunizing an animal with a peptide comprising an amino acid sequence ofSEQ ID NO: 2, SEQ ID NO: 4, SEQ ID NO: 6, SEQ ID NO: 8, SEQ ID NO: 10,SEQ ID NO: 12, SEQ ID NO: 14, or SEQ ID NO: 16.

Also provided is the hybridoma that produces a monoclonal antibody thatbinds to a peptide comprising an amino acid sequence of SEQ ID NO: 2

The present invention also provides for a method of detecting orquantitating the amount of MK61 polypeptide in a sample comprisingcontacting a sample suspected of containing MK61 polypeptide with theanti-MK61 antibody or antibody fragment set forth herein and detectingthe binding of said antibody or antibody fragment.

Additionally provided by the invention are selective binding agents orfragments thereof that are capable of specifically binding the MK61polypeptides, derivatives, variants, and fragments (preferably havingsequences of at least about 25 amino acids) thereof. These selectivebinding agents may be antibodies such as humanized antibodies, humanantibodies, polyclonal antibodies, monoclonal antibodies, chimericantibodies, complementarity determining region (CDR)-grafted antibodies,anti-idiotypic antibodies, and fragments thereof. Furthermore, theselective binding agents may be antibody variable region fragments, suchas Fab or Fab′ fragments, or fragments thereof, and may comprise atleast one complementarity determining region with specificity for a MK61polypeptide set forth herein. The selective binding agent may also bebound to a detectable label, such as a radiolabel, a fluorescent label,an enzyme label, or any other label known in the art. Further, theselective binding agent may antagonize MK61 polypeptide biologicalactivity, and/or be produced by immunizing an animal with a MK61polypeptide as set forth herein.

The present invention also provides for a hybridoma that produces aselective binding agent capable of binding MK61 polypeptide as set forthherein.

Also provided is a method for treating, preventing, or ameliorating adisease, condition, or disorder comprising administering to a patient aneffective amount of a selective binding agent as set forth herein. Aneffective amount, or a therapeutically effective amount, is an amountsufficient to result in a detectable change in the course or magnitudeof the disease, condition or disorder, such as the intensity or durationof presentment of any symptom associated therewith.

Pharmaceutical compositions comprising the above-described nucleic acidmolecules, polypeptides or selective binding agents and one or morepharmaceutically acceptable formulation agents are also encompassed bythe invention. The pharmaceutical acceptable formulation agent may be acarrier, adjuvant, soubilizer, stabilizer, or anti-oxidant. The nucleicacid molecules of the present invention may be contained in viralvectors. The compositions are used to provide therapeutically effectiveamounts of the nucleic acid molecules or polypeptides of the presentinvention. The invention is also directed to methods of using thepolypeptides, nucleic acid molecules, and selective binding agents.

Also provided are derivatives of the MK61 polypeptides of the presentinvention. These polypeptides may be covalently modified with awater-soluble polymer wherein the water-soluble polymer is selected fromthe group consisting of polyethylene glycol, monomethoxy-polyethyleneglycol, dextran, cellulose, poly-(N-vinyl pyrrolidone) polyethyleneglycol, propylene glycol homopolymers, polypropylene oxide/ethyleneoxide co-polymers, polyoxyethylated polyols, and polyvinyl alcohol.

The present invention also provides for fusion polypeptides comprisingthe polypeptide sequences set forth herein fused to a heterologous aminoacid sequence, which may be an IgG constant domain or fragment thereof.

Methods for treating, preventing or ameliorating a medical condition,such as cancer, in a mammal resulting from decreased levels of MK61polypeptide are also included in the present invention. These methodsinclude administering to a patient a therapeutically effective amount ofan antagonist selected from the group consisting of selective bindingagents, small molecules, peptides, peptide derivatives and antisenseoligonucleotides. These medical conditions may include thosecharacterized by immune system stimulation such as autoimmune diseasesand leukemias and lymphomas.

Methods for treating, preventing or ameliorating a medical condition ina mammal resulting from increased levels of MK61 polypeptide are alsoincluded in the present invention. These methods comprise administeringto a patient a therapeutically effective amount of a MK61 polypeptide; anucleic acid molecule encoding a MK61 polypeptide; or a nucleic acidmolecule comprising elements that regulate or modulate the expression ofa MK61 polypeptide. Examples of these methods include gene therapy andcell therapy and are further described herein. These medical conditionsmay include those characterized by immune system suppression such asAIDs and cancers.

The invention encompasses methods of diagnosing a pathological conditionor a susceptibility to a pathological condition in a subject caused byor resulting from abnormal levels of MK61 polypeptide comprisingdetermining the presence or amount of expression of the MK61 polypeptidein a biological, tissue, or cellular sample; and comparing the level ofsaid polypeptide in a biological, tissue, or cellular sample from eithernormal subjects or the subject at a different time, whereinsusceptibility to a pathological condition is based on the presence oramount of expression of the polypeptide.

The MK61 polypeptides and nucleic acid molecules of the presentinvention may be used to treat, prevent, ameliorate and/or detectdiseases and disorders, including those recited herein.

The present invention also provides a method of identifying coumpoundswhich bind to a MK61 polypeptide. The method comprises contacting anMK61 polypeptide with a test molecule and determining the extent ofbinding of the test molecule to the polypeptide. The method may furthercomprise determining whether such test molecules are agonists orantagonists of an MK61 polypeptide. The present invention furtherprovides a method of testing the impact of molecules on the expressionof an MK61 polypeptide or on the activity of an MK61 polypeptide.

Methods of regulating expression and modulating (i.e., increasing ordecreasing) levels of an MK61 polypeptide are also encompassed by theinvention. One method comprises administering to an animal a nucleicacid molecule encoding an MK61 polypeptide. In another method, a nucleicacid molecule comprising elements that regulate or modulate theexpression of an MK61 polypeptide may be administered. Examples of thesemethods include gene therapy, cell therapy and anti-sense therapy asfurther described herein.

The present invention further provides a method of modulating levels ofa MK61 polypeptide in an animal comprising administering to the animalthe nucleic acid molecule set forth herein.

A transgenic non-human animal comprising a nucleic acid moleculeencoding a MK61 polypeptide is also encompassed by the invention. TheMK61 nucleic acid molecule is introduced into the animal in a mannerthat allows expression and increased levels of the MK61 polypeptide,which may include increased circulating levels. The transgenic non-humananimal is preferably a mammal.

The present invention provides for a diagnostic reagent comprising adetectably labeled polynucleotide encoding the amino acid sequence setout in SEQ ID NO: 2, or a fragment, variant or homolog thereof,including allelic variants and spliced variants thereof. The detectablylabeled polynucleotide may be a first-strand cDNA, DNA, or RNA.

The invention also provides a method for detecting the presence of MK61nucleic acid molecules in a biological sample comprising the steps of:

(a) providing a biological sample suspected of containing MK61 nucleicacid molecules;

(b) contacting the biological sample with a diagnostic reagent underconditions wherein the diagnostic reagent will hybridize with MK61nucleic acid molecules contained in said biological sample;

(c) detecting hybridization between MK61 nucleic acid molecules in thebiological sample and the diagnostic reagent; and

(d) comparing the level of hybridization between the biological sampleand diagnostic reagent with the level of hybridization between a knownconcentration of MK61 nucleic acid molecules and the diagnostic reagent.

The invention also provides a method for detecting the presence of MK61nucleic acid molecules in a tissue or cellular sample comprising thesteps of:

(a) providing a tissue or cellular sample suspected of containing MK61nucleic acid molecules;

(b) contacting the tissue or cellular sample with a diagnostic reagentunder conditions wherein the diagnostic reagent will hybridize with MK61nucleic acid molecules;

(c) detecting hybridization between MK61 nucleic acid molecules in thetissue or cellular sample and the diagnostic reagent; and

(d) comparing the level of hybridization between the tissue or cellularsample and diagnostic reagent with the level of hybridization between aknown concentration of MK61 nucleic acid molecules and the diagnosticreagent.

The invention provides for methods of inhibiting MK61 receptor activityin a mammal comprising administering at least one of the amino acidsequences selected from the group consisting of SEQ ID NOS: 2, 4, 6, 8,10, 12, 14, 16, 36 and 38.

The invention provides for methods of inhibiting MK61 ligand activity ina mammal comprising administering at least one of the amino acidsequences selected from the group consisting of SEQ ID NOS: 2, 4, 6, 8,10, 12, 14, 16, 36 and 38.

The invention provides for methods of stimulating an immune response ina mammal by administering a negative regulator of MK61 receptorsignaling. A negative regulator is a molecule which inhibits thesignaling of the MK61 receptor. Negative regulators include but are notlimited to fusion proteins, such as those set out in SEQ ID NOS: 16, 36and 39, antibodies, small molecules, peptides and peptide derivatives.

The invention also provides for methods of inhibiting an immune responsecomprising administering a positive regulator or MK61 receptorsignaling. A positive regulator is a molecule which activates thesignaling of MK61 receptor. Positive regulators include MK61 ligands andagonistic antibodies.

The invention provides for methods of stimulating reverse signalingthrough a cell surface bound MK61 ligand comprising a positive regulatorof MK61 ligand reverse signaling. The positive regulators include butare not limited to MK61 fusion proteins, antibodies, small molecules andpeptide derivatives. The term “reverse signaling” refers to activationof cellular signaling induced by a molecule binding to a cell surfacebound ligand such as binding by the ligand's receptor or an anti-ligandantibody.

The invention also provides for methods of inhibiting reverse signalingthrough a cell surface bound MK61 ligand comprising a negative regulatorof MK61 ligand reverse signaling. The negative regulators include butare not limited to MK61 fusion proteins, antibodies, small molecules andpeptide derivatives.

The invention provides for methods of treating a B cell or T celllymphoproliferative disorder, an autoimmune disease or an inflammatorydisease in a mammal comprising administering a therapeutically effectiveamount of MK61-Fc fusion protein, an anti-MK-61 antibody, an antisenseoligonucleotide, a MK61 ligand, or a anti-MK61 ligand antibody to saidmammal. The lymphoproliferative diseases that may be treated include butare not limited to myeloma; B lymphoma, leukemia; and non-hodgkinslymphoma. The autoimmune diseases include but are not limited torheumatoid arthritis, systemic lupus erythematosus, intestinal boweldisease and Crohn's Disease. The inflammatory diseases include but arenot limited to rheumatoid arthritis, sepsis, intestinal bowel diseaseand Crohn's Disease.

The invention also encompasses a polypeptide fragment having an aminoacid sequence comprising the cysteine rich domain residues 26-60 of SEQID NO: 36. The cysteine rich domain matches the TNFR superfamilycysteine-rich region signature as defined in Madry et. al (Intl.Immunol. 10:1693-1702, 1998) and references therein and is expected toencompass the MK61 ligand-binding domain.

The MK61 polypeptides can be used for identifying ligands thereof.Various forms of “expression cloning” have been used for cloning ligandsfor receptors, see e.g., Davis et al., Cell, 87:1161-1169 (1996). Theseand other MK61 ligand cloning experiments are described in greaterdetail herein. Isolation of the MK61 ligand(s) allows for theidentification or development of novel agonists and/or antagonists ofthe MK61 signaling pathway. Such agonists and antagonists include MK61ligand(s), anti-MK61 ligand antibodies and derivatives thereof, smallmolecules, carbohydrates, lipid, polynucleotides (including antisenseoligonucleotides), any of which can be used for potentially treating oneor more diseases or disorders, including those recited herein.

BRIEF DESCRIPTION OF THE FIGURES

It will be understood that in the figures described below, thenucleotides 5′ to those nucleotides encoding the signal peptide are partof the 5′-untranslated (5′-UTR) flanking sequence. Additionally,nucleotides 3′ to the stop codon represent the 3′-untranslated (3′-UTR)sequence.

FIG. 1 depicts a nucleic acid sequence (SEQ ID NO:1) encoding humanMK61T1 (hMK61T1). Also depicted is the amino acid sequence (SEQ ID NO:2)of human hMK61T1. hMK61T1 is a cell surface receptor which contains asignal peptide (SP), one TNFr type cysteine rich domain (CRD), spacer,transmembrane domain (TM), and a long intracellular domain with tworegions highly conserved between species. The predicted signal peptideis underlined in this figure, and the stop codon in SEQ ID NO:1 isdouble-underlined.

FIG. 2 depicts a nucleic acid sequence (SEQ ID NO:3) encoding humanMK61T2 (hMK61T2), believed to be a soluble receptor. Also depicted isthe amino acid sequence (SEQ ID NO:4) of human hMK61T2. The predictedsignal peptide is underlined in this figure, and the stop codon in SEQID NO:3 is double-underlined.

FIG. 3 depicts a nucleic acid sequence (SEQ ID NO:5) encoding humanMK61T3 (hMK61T3). Also depicted is the amino acid sequence (SEQ ID NO:6)of human hMK61T3. hMK61T3 is believed to be a soluble receptor, having asignal peptide and TNFr-type CRD. The predicted signal peptide isunderlined in this figure, and the stop codon in SEQ ID NO:5 isdouble-underlined.

FIG. 4 depicts a nucleic acid sequence (SEQ ID NO:7) and amino acidsequence (SEQ ID NO:8) encoding human MK61T4 (hMK61T4), believed to be asoluble receptor. The predicted signal peptide is underlined in thisfigure, and the stop codon in SEQ ID NO:7 is double-underlined.

FIG. 5 depicts a nucleic acid sequence (SEQ ID NO:9) and amino acidsequence (SEQ ID NO:10) encoding human MK61T5 (hMK61T5), believed to bea soluble receptor. The predicted signal peptide is underlined in thisfigure, and the stop codon in SEQ ID NO:9 is double-underlined.

FIG. 6 depicts a nucleic acid sequence (SEQ ID NO:11) and amino acidsequence (SEQ ID NO:12) encoding human MK61T6 (hMK61T6), believed to bea soluble receptor. The predicted signal peptide is underlined in thisfigure, and the stop codon in SEQ ID NO:11 is double-underlined.

FIG. 7 depicts the nucleic acid sequence (SEQ ID NO:13) and amino acidsequence (SEQ ID NO:14) encoding mouse MK61 (mMK61), also called“Smil2-00051-F3”, or “Smil2-00051”. In this figure, the predicted signalpeptide is underlined, and the stop codon in SEQ ID NO:13 isdouble-underlined.

FIG. 8 depicts the nucleic acid sequence (SEQ ID NO:15) and amino acidsequence (SEQ ID NO:16) encoding the mouse mMK61-Fc fusion polypeptide(mMK61-Fc). In this figure, the predicted signal peptide is underlined,the Fc portion of the sequence is double-underlined, the NotI restrictsite for joining MK61 to Fc is in bold, and the Kozak consensus sequence(which is not translated) is in italics.

FIG. 9 sets forth a Western Blot showing that the mMK61 Fc fusionprotein (mMK61-Fc) is capable of being secreted from mammalian cells.

FIG. 10 sets forth an amino acid comparison of mMK61 (SEQ ID NO:14) withan OPG receptor, Mrank, (SEQ ID NO:17), a known TNFr family member.Mrank is the mouse OPG (osteoprotegerin) receptor precursor.

FIG. 11 sets forth an amino acid comparison of mMK61 (SEQ ID NO:14) withthe Fas ligand receptor (mfas), (SEQ ID NO:18). mfas is anapoptosis-mediating surface antigen receptor precursor.

FIG. 12 sets forth an amino acid comparison of mMK61 (SEQ ID NO:14) witha known mouse lymphotoxin-beta receptor (Tnfrc), SEQ ID NO.:19. Tnfrc isa lymphotoxin-beta receptor precursor, and is also called “tumornecrosis factor receptor 2 related protein” or “tumor necrosis factor-creceptor precursor”.

FIGS. 13 and 14 depict multiple tissue Northern blots which were probedwith a random primed human MK61 radioactive probe. These blotsdemonstrate that human MK61 mRNA is expressed in human lymphoid tissues.

FIG. 15 depicts a histogram comparing human MK61 mRNA expression invarious human tissues and cell lines as measured by quantitative PCR.

FIG. 16 depicts histograms quantitating the binding of the MK61-Fcfusion protein on the surface of human cells as measured by FACSanalysis. The histograms indicate that MK61-Fc fusion protein binds tothe cell surface of U937 and Jurkat cells.

FIG. 17 displays histograms demonstrating enhanced binding of theMK61-Fc fusion protein on the cell surface of Jurkat and U937 cellsafter treatment with interferon gamma.

FIG. 18 depicts histograms quantitating the production of IgG (toppanel) and IgA (bottom panel) in mouse splenocyte cultures aftertreatment with MK61-Fc fusion protein.

FIG. 19 depicts histograms quantitating the effect of MK61-Fc fusionprotein on spleen weights in mice (top panel) and spleen lymphocytes(bottom panel). These histograms demonstrate that treatment with theMK61-Fc fusion protein increased the spleen weight and the number ofspleen lyphocytes.

FIG. 20 depicts the histological analysis of the spleens of MK61-Fctreated mice. The histological analysis indicated the presence oflymphoid hyperplasia.

FIG. 21 depicts histograms quantitating the numbers of spleen B and Tcells in mice treated with MK61-Fc fusion protein.

FIG. 22 depicts histograms quantitating plasma immunoglobulin levels inmice treated with MK61-Fc fusion protein.

FIG. 23 depicts histograms quantitating the generation of anti-KLHspecific antibodies in mice treated with MK61-Fc fusion protein.

FIG. 24 sets out the amino acid sequence of the human MK61-delta Fc CHO(SEQ ID NO: 36).

FIG. 25 sets out the amino acid sequence of the human MK61-Fc CHO (SEQID NO: 39).

DETAILED DESCRIPTION OF THE INVENTION

The section headings used herein are for organizational purposes onlyand are not to be construed as limiting the subject matter described.All references cited in this application are expressly incorporated byreference herein.

The hMK61T1 isoform is a cell-surface receptor having a signal peptide,a TNF receptor (TNFR) cysteine rich domain (CRD), a transmembrane domain(TM), and a long and highly conserved intracellular domain.

The remaining five human isoforms (hMK61T2, hMK61T3, hMK61T4, hMK61TS,and hMK61T6) are believed to be soluble receptor forms of MK61. hMK61T3and hMK61T5 each contain a complete TNFr CRD, and are likelynaturally-occurring inhibitors of the hMK61T1 mediated signaltransduction. The hMK61T2, hMK61T4, and hMK61T6 isoforms each containpartial CRD's.

mMK61 is a mouse MK61 isoform, and mMK61-Fc is an Fc-fusion polypeptidethereof.

Definitions

The terms “MK61 gene” or “MK61 nucleic acid molecule” or“polynucleotide” refers to a nucleic acid molecule comprising orconsisting of a nucleotide sequence as set forth in SEQ ID NO:1, SEQ IDNO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13,or SEQ ID NO:15, a nucleotide sequence encoding the polypeptide as setforth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16, and nucleic acidmolecules as defined herein.

The term “MK61 polypeptide” refers to a polypeptide comprising the aminoacid sequence of SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16, and relatedpolypeptides. Related polypeptides include: MK61 polypeptide allelicvariants, MK61 polypeptide orthologs, MK61 polypeptide splice variants,MK61 polypeptide variants and MK61 polypeptide derivatives. MK61polypeptides may be mature polypeptides, as defined herein, and may ormay not have an amino terminal methionine residue, depending on themethod by which they are prepared.

The term “MK61 polypeptide allelic variant” refers to the polypeptideencoded by one of several possible naturally occurring alternate formsof a gene occupying a given locus on a chromosome of an organism or apopulation of organisms.

The term “MK61 polypeptide derivatives” refers to a polypeptide havingthe amino acid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ IDNO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ IDNO:16, MK61 polypeptide allelic variants, MK61 polypeptide orthologs,MK61 polypeptide splice variants, or MK61 polypeptide variants, asdefined herein, that have been chemically modified.

The term “MK61 polypeptide fragment “refers to a polypeptide thatcomprises a truncation at the amino terminus (with or without a leadersequence) and/or a truncation at the carboxy terminus of the polypeptidewhose sequence is as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6,SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16,MK61 polypeptide allelic variants, MK61 polypeptide orthologs, MK61polypeptide splice variants and/or an MK61 polypeptide variant havingone or more amino acid additions or substitutions or internal deletions(wherein the resulting polypeptide is at least six (6) amino acids ormore in length) as compared to the MK61 polypeptide amino acid sequenceset forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16. MK61 polypeptidefragments may result from alternative RNA splicing or from in vivoprotease activity. For transmembrane or membrane-bound forms of the MK61polypeptides, preferred fragments include soluble forms such as thoselacking a transmembrane or membrane-binding domain.

In preferred embodiments, truncations comprise about 10 amino acids, orabout 20 amino acids, or about 50 amino acids, or about 75 amino acids,or about 100 amino acids, or more than about 100 amino acids. Thepolypeptide fragments so produced will comprise about 25 contiguousamino acids, about 50 amino acids, or about 75 amino acids, or about 100amino acids, or about 150 amino acids, or about 200 amino acids. SuchMK61 polypeptide fragments may optionally comprise an amino terminalmethionine residue. It will be appreciated that such fragments can beused, for example, to generate antibodies to MK61 polypeptides.

The term “MK61 fusion polypeptide” refers to a fusion of one or moreamino acids (such as a heterologous peptide or polypeptide) at the aminoor carboxy terminus of the polypeptide as set forth in SEQ ID NO:2, SEQID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16, MK61 polypeptide allelic variants, MK61polypeptide orthologs, MK61 polypeptide splice variants, or MK61polypeptide variants having one or more amino acid deletions,substitutions or internal additions as compared to the MK61 polypeptideamino acid sequence set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6,SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16.

The term “MK61 polypeptide ortholog” refers to a polypeptide fromanother species that corresponds to an MK61 polypeptide amino acidsequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ IDNO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16. Forexample, mouse and human MK61 polypeptides are considered orthologs ofeach other.

The term “MK61 polypeptide splice variant” refers to a nucleic acidmolecule, usually RNA, which is generated by alternative processing ofintron sequences in an RNA primary transcript containing thenon-contiguous coding region of the MK61 polypeptide amino acid sequenceas set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16.

The term “MK61 polypeptide variants” refers to MK61 polypeptidescomprising amino acid sequences having one or more amino acid sequencesubstitutions, deletions (such as internal deletions and/or MK61polypeptide fragments), and/or additions (such as internal additionsand/or MK61 fusion polypeptides) as compared to the MK61 polypeptideamino acid sequences set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6,SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16(with or without a leader sequence). Variants may be naturally occurring(e.g., MK61 polypeptide allelic variants, MK61 polypeptide orthologs andMK61 polypeptide splice variants) or may be artificially constructed.Such MK61 polypeptide variants may be prepared from the correspondingnucleic acid molecules having a DNA sequence that varies accordinglyfrom the DNA sequence as set forth in SEQ ID NO:1, SEQ ID NO:3, SEQ IDNO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13, or SEQ IDNO:15. In preferred embodiments, the variants have from 1 to 3, or from1 to 5, or from 1 to 10, or from 1 to 15, or from 1 to 20, or from 1 to25, or from 1 to 50, or from 1 to 75, or from 1 to 100, or more than 100amino acid substitutions, insertions, additions and/or deletions,wherein the substitutions may be conservative, or non-conservative, orany combination thereof.

The term “antigen” refers to a molecule or a portion of a moleculecapable of being bound by a selective binding agent, such as anantibody, and additionally capable of being used in an animal to produceantibodies capable of binding to an epitope of each antigen. An antigenmay have one or more epitopes.

The term “biologically active MK61 polypeptides” refers to MK61polypeptides having at least one activity characteristic of thepolypeptide comprising the amino acid sequence of SEQ ID NO:2, SEQ IDNO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16.

The terms “effective amount” and “therapeutically effective amount” eachrefer to the amount of a MK61 polypeptide or MK61 nucleic acid moleculeused to support an observable level of one or more biological activitiesof the MK61 polypeptides as set forth herein.

The term “expression vector” refers to a vector which is suitable foruse in a host cell and contains nucleic acid sequences which directand/or control the expression of heterologous nucleic acid sequences.Expression includes, but is not limited to, processes such astranscription, translation, and RNA splicing, if introns are present.

The term “host cell” is used to refer to a cell which has beentransformed, or is capable of being transformed with a nucleic acidsequence and then of expressing a selected gene of interest. The termincludes the progeny of the parent cell, whether or not the progeny isidentical in morphology or in genetic make-up to the original parent, solong as the selected gene is present.

The term “identity” as known in the art refers to a relationship betweenthe sequences of two or more polypeptide molecules or two or morenucleic acid molecules, as determined by comparing the sequences. In theart, “identity” also means the degree of sequence relatedness betweennucleic acid molecules or polypeptides, as the case may be, asdetermined by the match between strings of two or more nucleotide or twoor more amino acid sequences. “Identity” measures the percent ofidentical matches between the smaller of two or more sequences with gapalignments (if any) addressed by a particular mathematical model orcomputer program (i.e., “algorithms”).

The term “similarity” is a related concept but, in contrast to“identity”, refers to a measure of similarity which includes bothidentical matches and conservative substitution matches. If twopolypeptide sequences have, for example, 10/20 identical amino acids,and the remainder are all non-conservative substitutions, then thepercent identity and similarity would both be 50%. If, in the sameexample, there are five more positions where there are conservativesubstitutions, then the percent identity remains 50%, but the percentsimilarity would be 75% (15/20). Therefore, in cases where there areconservative substitutions, the degree of percent similarity between twopolypeptides will be higher than the percent identity between those twopolypeptides.

The term “isolated nucleic acid molecule” refers to a nucleic acidmolecule of the invention that (1) has been separated from at leastabout 50 percent of proteins, lipids, carbohydrates or other materialswith which it is naturally found when total DNA is isolated from thesource cells, (2) is not linked to all or a portion of a polynucleotideto which the “isolated nucleic acid molecule” is linked in nature, (3)is operably linked to a polynucleotide which it is not linked to innature, or (4) does not occur in nature as part of a largerpolynucleotide sequence. Preferably, the isolated nucleic acid moleculeof the present invention is substantially free from any othercontaminating nucleic acid molecule(s) or other contaminants that arefound in its natural environment that would interfere with its use inpolypeptide production or its therapeutic, diagnostic, prophylactic orresearch use.

The term “isolated polypeptide” refers to a polypeptide of the presentinvention that (1) has been separated from at least about 50 percent ofpolynucleotides, lipids, carbohydrates or other materials with which itis naturally found when isolated from the source cell, (2) is not linked(by covalent or noncovalent interaction) to all or a portion of apolypeptide to which the “isolated polypeptide” is linked in nature, (3)is operably linked (by covalent or noncovalent interaction) to apolypeptide with which it is not linked in nature, or (4) does not occurin nature. Preferably, the isolated polypeptide is substantially freefrom any other contaminating polypeptides or other contaminants that arefound in its natural environment that would interfere with itstherapeutic, diagnostic, prophylactic or research use.

The term “mature MK61 polypeptide” refers to an MK61 polypeptide lackinga leader sequence. A mature MK61 polypeptide may also include othermodifications such as proteolytic processing of the amino terminus (withor without a leader sequence) and/or the carboxy terminus, cleavage of asmaller polypeptide from a larger precursor, N-linked and/or O-linkedglycosylation, and the like.

An exemplary mature MK61 polypeptide is depicted by amino acid residue24 through amino acid residue 355 of SEQ ID NO:2; by amino acid residue24 through amino acid residue 85 of SEQ ID NO:4; by amino acid residue24 through amino acid residue 136 of SEQ ID NO:6; by amino acid residue24 through amino acid residue 187 of SEQ ID NO:8; by amino acid residue24 through amino acid residue 71 of SEQ ID NO:10; by amino acid residue24 through amino acid residue 167 of SEQ ID NO:12; by amino acid residue22 through amino acid residue 345 of SEQ ID NO:14; and by amino acidresidue 22 through amino acid residue 404 of SEQ ID NO:16.

The terms “nucleic acid sequence” or “nucleic acid molecule” refer to aDNA or RNA sequence. The terms encompass molecules formed from any ofthe known base analogs of DNA and RNA such as, but not limited to4-acetylcytosine, 8-hydroxy-N6-methyladenine, aziridinyl-cytosine,pseudoisocytosine, 5-(carboxyhydroxylmethyl) uracil, 5-fluorouracil,5-bromouracil, 5-carboxymethylaminomethyl-2-thiouracil,5-carboxy-methylaminomethyluracil, dihydrouracil, inosine,N6-iso-pentenyladenine, 1-methyladenine, 1-methylpseudouracil,1-methylguanine, 1-methylinosine, 2,2-dimethyl-guanine, 2-methyladenine,2-methylguanine, 3-methylcytosine, 5-methylcytosine, N6-methyladenine,7-methylguanine, 5-methylaminomethyluracil,5-methoxyamino-methyl-2-thiouracil, beta-D-mannosylqueosine,5′-methoxycarbonyl-methyluracil, 5-methoxyuracil,2-methylthio-N6-isopentenyladenine, uracil-5-oxyacetic acid methylester,uracil-5-oxyacetic acid, oxybutoxosine, pseudouracil, queosine,2-thiocytosine, 5-methyl-2-thiouracil, 2-thiouracil, 4-thiouracil,5-methyluracil, N-uracil-5-oxyacetic acid methylester,uracil-5-oxyacetic acid, pseudouracil, queosine, 2-thiocytosine, and2,6-diaminopurine.

The term “naturally occurring” or “native” when used in connection withbiological materials such as nucleic acid molecules, polypeptides, hostcells, and the like, refer to materials which are found in nature andare not manipulated by man. Similarly, “non-naturally occurring” or“non-native” as used herein refers to a material that is not found innature or that has been structurally modified or synthesized by man.

The term “operably linked” is used herein to refer to a method offlanking sequences wherein the flanking sequences so described areconfigured or assembled so as to perform their usual function. Thus, aflanking sequence operably linked to a coding sequence may be capable ofeffecting the replication, transcription and/or translation of thecoding sequence. For example, a coding sequence is operably linked to apromoter when the promoter is capable of directing transcription of thatcoding sequence. A flanking sequence need not be contiguous with thecoding sequence, so long as it functions correctly. Thus, for example,intervening untranslated yet transcribed sequences can be presentbetween a promoter sequence and the coding sequence, and the promotersequence can still be considered “operably linked” to the codingsequence.

The terms “pharmaceutically acceptable carrier” or “physiologicallyacceptable carrier” as used herein refer to one or more formulationmaterials suitable for accomplishing or enhancing the delivery of theMK61 polypeptide, MK61 nucleic acid molecule or MK61 selective bindingagent as a pharmaceutical composition.

The term “selective binding agent” refers to a molecule or moleculeshaving specificity for an MK61 polypeptide. As used herein the terms,“specific” and “specificity” refer to the ability of the selectivebinding agents to bind to human MK61 polypeptides and not to bind tohuman non-MK61 polypeptides. It will be appreciated, however, that theselective binding agents may also bind orthologs of the polypeptide asset forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16, that is,interspecies versions thereof, such as mouse and rat polypeptides.

The term “transduction” is used to refer to the transfer of nucleicacids from one bacterium to another, usually by a phage. “Transduction”also refers to the acquisition and transfer of eukaryotic cellularsequences by retroviruses.

The term “transfection” is used to refer to the uptake of foreign orexogenous DNA by a cell, and a cell has been “transfected” when theexogenous DNA has been introduced inside the cell membrane. A number oftransfection techniques are well known in the art and are disclosedherein. See, for example, Graham et al., Virology, 52:456 (1973);Sambrook et al., Molecular Cloning, a Laboratory Manual, Cold SpringHarbor Laboratories, New York, (1989); Davis et al., Basic Methods inMolecular Biology, Elsevier, (1986); and Chu et al., Gene, 13:197(1981). Such techniques can be used to introduce one or more exogenousDNA moieties into suitable host cells.

The term “transformation” as used herein refers to a change in a cellsgenetic characteristics, and a cell has been transformed when it hasbeen modified to contain new DNA. For example, a cell is transformedwhere it is genetically modified from its native state. Followingtransfection or transduction, the transforming DNA may recombine withthat of the cell by physically integrating into a chromosome of thecell, it may be maintained transiently as an episomal element withoutbeing replicated, or it may replicate independently as a plasmid. A cellis considered to have been stably transformed when the DNA is replicatedwith the division of the cell.

The term “vector” is used to refer to any molecule (e.g., nucleic acid,plasmid or virus) used to transfer coding information to a host cell.

Relatedness of Nucleic Acid Molecules and/or Polypeptides

It is understood that related nucleic acid molecules include allelic orsplice variants of the nucleic acid molecule of SEQ ID NO:1, SEQ IDNO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13,or SEQ ID NO:15, and include sequences which are complementary to any ofthe above nucleotide sequences. Related nucleic acid molecules alsoinclude a nucleotide sequence encoding a polypeptide comprising orconsisting essentially of a substitution, modification, addition and/ordeletion of one or more amino acid residues compared to the polypeptidein SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQID NO:12, SEQ ID NO:14, or SEQ ID NO:16.

Fragments include molecules which encode a polypeptide of at least about25 amino acid residues, or about 50, or about 75, or about 100,orgreater than about 100, amino acid residues of the polypeptide of SEQ IDNO:2.

In addition, related MK61 nucleic acid molecules include those moleculeswhich comprise nucleotide sequences which hybridize under moderately orhighly stringent conditions as defined herein with the fullycomplementary sequence of the nucleic acid molecule of SEQ ID NO:1, SEQID NO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ IDNO:13, or SEQ ID NO:15, or of a molecule encoding a polypeptide, whichpolypeptide comprises the amino acid sequence as shown in SEQ ID NO:2,SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQID NO:14, or SEQ ID NO:16, or of a nucleic acid fragment as definedherein, or of a nucleic acid fragment encoding a polypeptide as definedherein. Hybridization probes may be prepared using the MK61 sequencesprovided herein to screen cDNA, genomic or synthetic DNA libraries forrelated sequences. Regions of the DNA and/or amino acid sequence of MK61polypeptide that exhibit significant identity to known sequences arereadily determined using sequence alignment algorithms as describedherein, and those regions may be used to design probes for screening.

The term “highly stringent conditions” refers to those conditions thatare designed to permit hybridization of DNA strands whose sequences arehighly complementary, and to exclude hybridization of significantlymismatched DNAs. Hybridization stringency is principally determined bytemperature, ionic strength and the concentration of denaturing agentssuch as formamide. Examples of “highly stringent conditions” forhybridization and washing are 0.015M sodium chloride, 0.0015M sodiumcitrate at 65-68° C. or 0.015M sodium chloride, 0.0015M sodium citrate,and 50% formamide at 42° C. See Sambrook, Fritsch & Maniatis, MolecularCloning: A Laboratory Manual, 2^(nd) Ed., Cold Spring Harbor Laboratory,Cold Spring Harbor, N.Y. (1989) and Anderson et al., Nucleic AcidHybridization: a practical approach, Ch. 4, IRL Press Limited, Oxford,England (1985).

More stringent conditions (such as higher temperature, lower ionicstrength, higher formamide, or other denaturing agent) may also be used;however, the degree of hybridization will be affected. Other agents maybe included in the hybridization and washing buffers for the purpose ofreducing non-specific and/or background hybridization. Examples are 0.1%bovine serum albumin, 0.1% polyvinyl-pyrrolidone, 0.1% sodiumpyrophosphate, 0.1% sodium dodecylsulfate (NaDodSO₄ or SDS), ficoll,Denhardt's solution, sonicated salmon sperm DNA (or anothernon-complementary DNA), and dextran sulfate, although other suitableagents can also be used. The concentration and types of these additivescan be changed without substantially affecting the stringency of thehybridization conditions. Hybridization experiments are usually carriedout at pH 6.8-7.4; however, at typical ionic strength conditions, therate of hybridization is nearly independent of pH. See Anderson et al.,Nucleic Acid Hybridization: a Practical Approach, Ch. 4, IRL. PressLimited, Oxford, England (1985).

Factors affecting the stability of a DNA duplex include basecomposition, length, and degree of base pair mismatch. Hybridizationconditions can be adjusted by one skilled in the art in order toaccommodate these variables and allow DNAs of different sequencerelatedness to form hybrids. The melting temperature of a perfectlymatched DNA duplex can be estimated by the following equation:T_(m)(° C.)=81.5+16.6(log [Na+])+0.41(% G+C)−600/N−0.72(% formamide)where N is the length of the duplex formed in nucleotides, [Na+] is themolar concentration of the sodium ion in the hybridization or washingsolution, and % G+C is the percentage of (guanine+cytosine) bases in thehybrid. For imperfectly matched hybrids, the melting temperature isreduced by approximately 1° C. for each 1% mismatch.

The term “moderately stringent conditions” refers to conditions underwhich a DNA duplex with a greater degree of base pair mismatching thancould occur under “highly stringent conditions” is able to form.Examples of typical “moderately stringent conditions” are 0.015M sodiumchloride, 0.0015M sodium citrate at 50-65° C. or 0.015M sodium chloride,0.0015M sodium citrate, and 20% formamide at 37-50° C. By way ofexample, a “moderately stringent” condition of 50° C. in 0.015 M sodiumion will allow about a 21% mismatch.

It will be appreciated by those skilled in the art that there is noabsolute distinction between highly” and “moderately” stringentconditions. For example, at 0.015M sodium ion (no formamide), themelting temperature of perfectly matched long DNA is about 71° C. With awash at 65° C. (at the same ionic strength), this would allow forapproximately a 6% mismatch. To capture more distantly relatedsequences, one skilled in the art can simply lower the temperature orraise the ionic strength.

A good estimate of the melting temperature in 1M NaCl* foroligonucleotide probes up to about 20 nucleotides is given by:Tm=2° C. per A−T base pair+4° C. per G−C base pair*The sodium ion concentration in 6×salt sodium citrate (SSC) is 1M. SeeSuggs et al., Developmental Biology Using Purified Genes, p. 683, Brownand Fox (eds.) (1981).

High stringency washing conditions for oligonucleotides are usually at atemperature of 0-5° C. below the Tm of the oligonucleotide in 6×SSC,0.1% SDS for longer oligonucleotides.

In another embodiment, related nucleic acid molecules comprise orconsist of a nucleotide sequence that is about 70 percent (70%)identical to the nucleotide sequence as shown in SEQ ID NO:1, SEQ IDNO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13,or SEQ ID NO:15, or comprise or consist essentially of a nucleotidesequence encoding a polypeptide that is about 70 percent (70%) identicalto the polypeptide as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ IDNO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ IDNO:16. In preferred embodiments, the nucleotide sequences are about 75percent, or about 80 percent, or about 85 percent, or about 90 percent,or about 95, 96, 97, 98, or 99 percent identical to the nucleotidesequence as shown in SEQ ID NO:1, or the nucleotide sequences encode apolypeptide that is about 75 percent, or about 80 percent, or about 85percent, or about 90 percent, or about 95, 96, 97, 98, or 99 percentidentical to the polypeptide sequence as set forth in SEQ ID NO:2, SEQID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16.

Differences in the nucleic acid sequence may result in conservativeand/or non-conservative modifications of the amino acid sequencerelative to the amino acid sequence of SEQ ID NO:2, SEQ ID NO:4, SEQ IDNO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ IDNO:16.

Conservative modifications to the amino acid sequence of SEQ ID NO:2,SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQID NO:14, or SEQ ID NO:16 (and corresponding modifications to theencoding nucleotides) will produce MK61 polypeptides having functionaland chemical characteristics similar to those of a naturally occurringMK61 polypeptide. In contrast, substantial modifications in thefunctional and/or chemical characteristics of MK61 polypeptides may beaccomplished by selecting substitutions in the amino acid sequence ofSEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16 that differ significantly in theireffect on maintaining (a) the structure of the molecular backbone in thearea of the substitution, for example, as a sheet or helicalconformation, (b) the charge or hydrophobicity of the molecule at thetarget site, or (c) the bulk of the side chain.

For example, a “conservative amino acid substitution” may involve asubstitution of a native amino acid residue with a nonnative residuesuch that there is little or no effect on the polarity or charge of theamino acid residue at that position. Furthermore, any native residue inthe polypeptide may also be substituted with alanine, as has beenpreviously described for “alanine scanning mutagenesis.”

Conservative amino acid substitutions also encompass non-naturallyoccurring amino acid residues which are typically incorporated bychemical peptide synthesis rather than by synthesis in biologicalsystems. These include peptidomimetics and other reversed or invertedforms of amino acid moieties.

Naturally occurring residues may be divided into classes based on commonside chain properties:

-   -   1) hydrophobic: norleucine, Met, Ala, Val, Leu, Ile;    -   2) neutral hydrophilic: Cys, Ser, Thr, Asn, Gln;    -   3) acidic: Asp, Glu;    -   4) basic: His, Lys, Arg;    -   5) residues that influence chain orientation: Gly, Pro; and    -   6) aromatic: Trp, Tyr, Phe.

For example, non-conservative substitutions may involve the exchange ofa member of one of these classes for a member from another class. Suchsubstituted residues may be introduced into regions of the human MK61polypeptide that are homologous, or similar, with non-human MK61polypeptide orthologs, or into the non-homologous regions of themolecule.

In making such changes, the hydropathic index of amino acids may beconsidered. Each amino acid has been assigned a hydropathic index on thebasis of its hydrophobicity and charge characteristics. They are:isoleucine (+4.5); valine (+4.2); leucine (+3.8); phenylalanine (+2.8);cysteine/cystine (+2.5); methionine (+1.9); alanine (+1.8); glycine(−0.4); threonine (−0.7); serine (−0.8); tryptophan (−0.9); tyrosine(−1.3); proline (−1.6); histidine (−3.2); glutamate (−3.5); glutamine(−3.5); aspartate (−3.5); asparagine (−3.5); lysine (−3.9); and arginine(−4.5).

The importance of the hydropathic amino acid index in conferringinteractive biological function on a protein is understood in the art.Kyte et al., J. Mcl. Biol., 157:105-131 (1982). It is known that certainamino acids may be substituted for other amino acids having a similarhydropathic index or score and still retain a similar biologicalactivity. In making changes based upon the hydropathic index, thesubstitution of amino acids whose hydropathic indices are within ±2 ispreferred, those which are within ±1 are particularly preferred, andthose within ±0.5 are even more particularly preferred.

It is also understood in the art that the substitution of like aminoacids can be made effectively on the basis of hydrophilicity,particularly where the biologically functional equivalent protein orpeptide thereby created is intended, in part, for use in immunologicalembodiments, as in the present case. The greatest local averagehydrophilicity of a protein, as governed by the hydrophilicity of itsadjacent amino acids, correlates with its immunogenicity andantigenicity, i.e., with a biological property of the protein.

The following hydrophilicity values have been assigned to these aminoacid residues: arginine (+3.0); lysine (+3.0); aspartate (+3.0±1);glutamate (+3.0±1); serine (+0.3); asparagine (+0.2); glutamine (+0.2);glycine (0); threonine (−0.4); proline (−0.5±1); alanine (−0.5);histidine (−0.5); cysteine (−1.0); methionine (−1.3); valine (−1.5);leucine (−1.8); isoleucine (−1.8); tyrosine (−2.3); phenylalanine (−2.5)and tryptophan (−3.4). In making changes based upon similarhydrophilicity values, the substitution of amino acids whosehydrophilicity values are within ±2 is preferred, those which are within±1 are particularly preferred, and those within ±0.5 are even moreparticularly preferred. One may also identify epitopes from primaryamino acid sequences on the basis of hydrophilicity. These regions arealso referred to as “epitopic core regions.”

Desired amino acid substitutions (whether conservative ornon-conservative) can be determined by those skilled in the art at thetime such substitutions are desired. For example, amino acidsubstitutions can be used to identify important residues of the MK61polypeptide, or to increase or decrease the affinity of the MK61polypeptides for their substrates, described herein.

Exemplary amino acid substitutions are set forth in Table I.

TABLE I Amino Acid Substitutions Original Exemplary Preferred ResiduesSubstitutions Substitutions Ala Val, Leu, Ile Val Arg Lys, Gln, Asn LysAsn Gln Gln Asp Glu Glu Cys Ser, Ala Ser Gln Asn Asn Glu Asp Asp GlyPro, Ala Ala His Asn, Gln, Lys, Arg Arg Ile Leu, Val, Met, Ala, Leu Phe,Norleucine Leu Norleucine, Ile, Ile Val, Met, Ala, Phe Lys Arg, 1,4Diamino- Arg butyric Acid, Gln, Asn Met Leu, Phe, Ile Leu Phe Leu, Val,Ile, Ala, Leu Tyr Pro Ala Gly Ser Thr, Ala, Cys Thr Thr Ser Ser Trp Tyr,Phe Tyr Tyr Trp, Phe, Thr, Ser Phe Val Ile, Met, Leu, Phe, Leu Ala,Norleucine

A skilled artisan will be able to determine suitable variants of thepolypeptide as set forth in SEQ ID NO:2 using well-known techniques. Foridentifying suitable areas of the molecule that may be changed withoutdestroying activity, one skilled in the art may target areas notbelieved to be important for activity. For example, when similarpolypeptides with similar activities from the same species or from otherspecies are known, one skilled in the art may compare the amino acidsequence of an MK61 polypeptide to such similar polypeptides. With sucha comparison, one can identify residues and portions of the moleculesthat are conserved among similar polypeptides. It will be appreciatedthat changes in areas of an MK61 polypeptide that are not conservedrelative to such similar polypeptides would be less likely to adverselyaffect the biological activity and/or structure of the MK61 polypeptide.One skilled in the art would also know that, even in relativelyconserved regions, one may substitute chemically similar amino acids forthe naturally occurring residues while retaining activity (conservativeamino acid residue substitutions). Therefore, even areas that may beimportant for biological activity or for structure may be subject toconservative amino acid substitutions without destroying the biologicalactivity or without adversely affecting the polypeptide structure.

Additionally, one skilled in the art can review structure-functionstudies identifying residues in similar polypeptides that are importantfor activity or structure. In view of such a comparison, one can predictthe importance of amino acid residues in an MK61 polypeptide thatcorrespond to amino acid residues which are important for activity orstructure in similar polypeptides. One skilled in the art may opt forchemically similar amino acid substitutions for such predicted importantamino acid residues of MK61 polypeptides.

One skilled in the art can also analyze the three-dimensional structureand amino acid sequence in relation to that structure in similarpolypeptides. In view of such information, one skilled in the art maypredict the alignment of amino acid residues of an MK61 polypeptide withrespect to its three dimensional structure. One skilled in the art maychoose not to make radical changes to amino acid residues predicted tobe on the surface of the protein, since such residues may be involved inimportant interactions with other molecules. Moreover, one skilled inthe art may generate test variants containing a single amino acidsubstitution at each desired amino acid residue. The variants can thenbe screened using activity assays know to those skilled in the art. Suchvariants could be used to gather information about suitable variants.For example, if one discovered that a change to a particular amino acidresidue resulted in destroyed, undesirably reduced, or unsuitableactivity, variants with such a change would be avoided. In other words,based on information gathered from such routine experiments, one skilledin the art can readily determine the amino acids where furthersubstitutions should be avoided either alone or in combination withother mutations.

The MK61 polypeptide analogs of the invention can be determined bycomparing the amino acid sequence of MK1 polypeptides with relatedfamily members. Exemplary MK61 polypeptide-related family members mayinclude, but are not limited to TNF receptor family members such asMrank (SEQ ID NO: 17), Fas ligand receptor family members such asMfasr(SEQ ID NO: 18), and lymphotoxin-beta receptor family members suchas TNFrc (SEQ ID NO: 19). This comparison can be accomplished by using aPileup alignment (Wisconsin GCG Program Package, ver. 8.1; as shown inFIGS. 10, 11 and 12) or an equivalent (overlapping) comparison withmultiple family members within conserved and non-conserved regions. Asshown in FIGS. 10-12, the predicted amino acid sequence of a mMK61polypeptide (SEQ ID NO: 14) is aligned with the known amino acidsequences of Mrank (SEQ ID NO: 17), Mfasr (SEQ ID NO: 18) and Tnfrc (SEQID NO: 19), respectively.

Other MK61 polypeptide analogs can be identified using these or othermethods known to those of skill in the art. These overlapping sequencesprovide guidance for conservative and non-conservative amino acidssubstitutions resulting in additional MK61 analogs. It will beappreciated that these amino acid substitutions can consist of naturallyoccurring or non-naturally occurring amino acids. For example, thealignments depicted in FIGS. 10-12, indicate potential MK61 analogs mayhave the Cys residue at position 38, 39,or 51 of SEQ ID NOS: 2, 4, 6, 8,10 and 12 substituted with a Ser or Ala residue; the Cys residue atposition 60 or 76 of SEQ ID NOS: 2 and 6 substituted with a Ser or Alaresidue; the Cys residue at position 41, 42, 54, 63 or 79 of SEQ ID NOS:14 and 16 substituted with a Ser or Ala residue; the Leu residue atposition 171 or 172 of SEQ ID NOS: 2 substituted with a norluecine, Ile,Val, Met, Ala or Phe; the Leu residue at position 178 or 180 of SEQ IDNOS: 14 and 16 substituted with a norluecine, Ile, Val, Met, Ala or Phe;and the Gly residue at position 141 or SEQ ID NO: 14 or 16 substitutedwith a Pro or Ala residue.

A number of scientific publications have been devoted to the predictionof secondary structure. See Moult J., Curr. Op. in Biotech.,7(4):422-427 (1996), Chou et al., Biochemistry, 13(2):222-245 (1974);Chou et al., Biochemistry, 113(2):211-222 (1974); Chou et al., Adv.Enzymol. Relat. Areas Mol. Biol., 47:45-148 (1978); Chou et al., Ann.Rev. Biochem., 47:251-276 and Chou et al., Biophys. J., 26:367-384(1979). Moreover, computer programs are currently available to assistwith predicting secondary structure. One method of predicting secondarystructure is based upon homology modeling. For example, two polypeptidesor proteins which have a sequence identity of greater than 30%, orsimilarity greater than 40% often have similar structural topologies.The recent growth of the protein structural database (PDB) has providedenhanced predictability of secondary structure, including the potentialnumber of folds within a polypeptide's or protein's structure. See Holmet al., Nucl. Acid. Res., 27(1):244-247 (1999). It has been suggested(Brenner et al., Curr. Op. Struct. Biol., 7(3):369-376 (1997)) thatthere are a limited number of folds in a given polypeptide or proteinand that once a critical number of structures have been resolved,structural prediction will become dramatically more accurate.

Additional methods of predicting secondary structure include “threading”(Jones, D., Curr. Opin. Struct. Biol., 7(3):377-87 (1997); Sippl et al.,Structure, 4(1) :15-19 (1996)), “profile analysis” (Bowie et al.,Science, 253:164-170 (1991); Gribskov et al., Meth. Enzym., 183:146-159(1990); Gribskov et al., Proc. Nat. Acad. Sci., 84(13):4355-4358(1987)), and “evolutionary linkage” (See Holm, supra (1999), andBrenner, supra (1997)).

Preferred MK61 polypeptide variants include glycosylation variantswherein the number and/or type of glycosylation site has been alteredcompared to the amino acid sequence set forth in SEQ ID NO:2, SEQ IDNO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16. In one embodiment, MK61 polypeptide variantscomprise a greater or a lesser number of N-linked glycosylation sitesthan the amino acid sequence set forth in SEQ ID NO:2, SEQ ID NO:4, SEQID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQID NO:16. An N-linked glycosylation site is characterized by thesequence: Asn-X-Ser or Asn-X-Thr, wherein the amino acid residuedesignated as X may be any amino acid residue except proline. Thesubstitution of amino acid residues to create this sequence provides apotential new site for the addition of an N-linked carbohydrate chain.Alternatively, substitutions which eliminate this sequence will removean existing N-linked carbohydrate chain. Also provided is arearrangement of N-linked carbohydrate chains wherein one or moreN-linked glycosylation sites (typically those that are naturallyoccurring) are eliminated and one or more new N-linked sites arecreated. Additional preferred MK61 variants include cysteine variantswherein one or more cysteine residues are deleted from or substitutedfor another amino acid (e.g., serine) as compared to the amino acidsequence set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ IDNO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16.Cysteine variants are useful when MK61 polypeptides must be refoldedinto a biologically active conformation such as after the isolation ofinsoluble inclusion bodies. Cysteine variants generally have fewercysteine residues than the native protein, and typically have an evennumber to minimize interactions resulting from unpaired cysteines.

The invention further provides polypeptides that comprise anepitope-bearing portion of a protein as shown in SEQ ID NO:2, SEQ IDNO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16. The term, “epitope” refers to a region of aprotein to which an antibody can bind. See e.g., Geysen et al., PNAS,USA 81:3998-4002 (1984). Epitopes can be linear or conformational, thelatter being composed of discontinuous regions of the protein that forman epitope upon folding of the protein. Linear epitopes are generally atleast 6 amino acid residues in length. Relatively short syntheticpeptides that mimic part of a protein sequence are routinely capable ofeliciting an antiserum that reacts with the partially mimicked protein.See, Sutcliffe et al., Science 219:660-666 (1983). Antibodies thatrecognize short, linear epitopes are particularly useful in analytic anddiagnostic applications that employ denatured protein, such as Westernblotting. See Tobin, Proc. Natl. Acad. Sci. USA, 76:4350-4356 (1979).Antibodies to short peptides may also recognize proteins in nativeconformation and will thus be useful for monitoring protein expressionand protein isolation, and in detecting MK61 proteins in solution, suchas by ELISA or in immunoprecipitation studies.

In addition, the polypeptide comprising the amino acid sequence of SEQID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ IDNO:12, SEQ ID NO:14, or SEQ ID NO:16, or an MK61 polypeptide variant maybe fused to a homologous polypeptide to form a homodimer or to aheterologous polypeptide to form a heterodimer. Heterologous peptidesand polypeptides include, but are not limited to: an epitope to allowfor the detection and/or isolation of an MK61 fusion polypeptide; atransmembrane receptor protein or a portion thereof, such as anextracellular domain, or a transmembrane and intracellular domain; aligand or a portion thereof which binds to a transmembrane receptorprotein; an enzyme or portion thereof which is catalytically active; apolypeptide or peptide which promotes oligomerization, such as a leucinezipper domain; a polypeptide or peptide which increases stability, suchas an immunoglobulin constant region; and a polypeptide which has atherapeutic activity different from the polypeptide comprising the aminoacid sequence as set forth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16, oran MK61 polypeptide variant.

Fusions can be made either at the amino terminus or at the carboxyterminus of the polypeptides comprising the amino acid sequence setforth in SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ IDNO:10, SEQ ID NO:12, or SEQ ID NO:14, or an MK61 polypeptide variant.Fusions may be direct with no linker or adapter molecule, or indirectusing a linker or adapter molecule. A linker or adapter molecule may beone or more amino acid residues, typically from about 20 to about 50amino acid residues. A linker or adapter molecule may also be designedwith a cleavage site for a DNA restriction endonuclease in an encodingpolynucleotide or for a protease to allow for the separation of thefused moieties. It will be appreciated that once constructed, the fusionpolypeptides can be derivatized according to the methods describedherein.

In a further embodiment of the invention, the polypeptide comprising theamino acid sequence of SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ IDNO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or an MK61 polypeptidevariant is fused to one or more domains of an Fc region of human IgG.Antibodies comprise two functionally independent parts, a variabledomain known as “Fab”, which binds antigens, and a constant domain knownas “Fc”, which is involved in effector functions such as complementactivation and attack by phagocytic cells. An Fc has a long serumhalf-life, whereas an Fab is short-lived. Capon et al., Nature,337:525-31 (1989). When constructed together with a therapeutic protein,an Fc domain can provide longer half-life or incorporate such functionsas Fc receptor binding, protein A binding, complement fixation andperhaps even placental transfer. Id. Table II summarizes the use ofcertain Fc fusions known in the art.

TABLE II Fc Fusion with Therapeutic Proteins Fusion Therapeutic Form ofFc partner implications Reference IgG1 N-terminus Hodgkin's U.S. Pat.No. of CD30-L disease; 5,480,981 anaplastic lymphoma; T-cell leukemiaMurine IL-10 anti- Zheng et al. Fcγ2a inflammatory; (1995), J.transplant Immunol., 154: rejection 5590-5600 IgG1 TNF septic shockFisher et al. receptor (1996), N. Engl. J. Med., 334: 1697-1702; Van Zeeet al., (1996), J. Immunol., 156: 2221-2230 IgG, IgA, TNF inflammation,U.S. Pat. No. IgM, or receptor autoimmune 5,808,029, issued IgEdisorders Sep. 15, 1998 (excluding the first domain) IgG1 CD4 AIDS Caponet al. receptor (1989), Nature 337: 525-531 IgG1, N-terminusanti-cancer, Harvill et al. IgG3 of IL-2 antiviral (1995), Immunotech.,1: 95-105 IgG1 C-terminus osteoarthritis; WO 97/23614, of OPG bonedensity published Jul. 3, 1997 IgG1 N-terminus anti-obesity PCT/US97/23183, of leptin filed Dec. 11, 1997 Human Ig CTLA-4 autoimmuneLinsley (1991), Cγ1 disorders J. Exp. Med., 174: 561-569

In one example, all or a portion of the human IgG hinge, CH₂ and CH₃regions may be fused at either the N-terminus or C-terminus of the MK61polypeptides using methods known to the skilled artisan. The resultingMK61 fusion polypeptide may be purified by use of a Protein A affinitycolumn. Peptides and proteins fused to an Fc region have been found toexhibit a substantially greater half-life in vivo than the unfusedcounterpart. Also, a fusion to an Fc region allows fordimerization/multimerization of the fusion polypeptide. The Fc regionmay be a naturally occurring Fc region, or may be altered to improvecertain qualities, such as therapeutic qualities, circulation time,reduce aggregation, etc.

Identity and similarity of related nucleic acid molecules andpolypeptides can be readily calculated by known methods. Such methodsinclude, but are not limited to, those described in ComputationalMolecular Biology, Lesk, A. M., ed., Oxford University Press, New York(1988); Biocomputing: Informatics and Genome Projects, Smith, D. W.,ed., Academic Press, New York (1993); Computer Analysis of SequenceData, Part 1, Griffin, A. M., and Griffin, H. G., eds., Humana Press,New Jersey (1994); Sequence Analysis in Molecular Biology, von Heinje,G., Academic Press (1987); Sequence Analysis Primer, Gribskov, M. andDevereux, J., eds., M. Stockton Press, New York (1991); and Carillo etal., SIAM J. Applied Math., 48:1073 (1988).

Preferred methods to determine identity and/or similarity are designedto give the largest match between the sequences tested. Methods todetermine identity and similarity are described in publicly availablecomputer programs. Preferred computer program methods to determineidentity and similarity between two sequences include, but are notlimited to, the GCG program package, including GAP (Devereux et al.,Nucl. Acid. Res., 12:387 (1984); Genetics Computer Group, University ofWisconsin, Madison, Wis., BLASTP, BLASTN, and FASTA (Altschul et al., J.Mol. Biol., 215:403-410 (1990)). The BLASTX program is publiclyavailable from the National Center for Biotechnology Information (NCBI)and other sources (BLAST Manual, Altschul et al. NCB/NLM/NIH Bethesda,Md. 20894; Altschul et al., supra (1990)). The well-known Smith Watermanalgorithm may also be used to determine identity.

Certain alignment schemes for aligning two amino acid sequences mayresult in the matching of only a short region of the two sequences, andthis small aligned region may have very high sequence identity eventhough there is no significant relationship between the two full-lengthsequences. Accordingly, in a preferred embodiment the selected alignmentmethod (GAP program) will result in an alignment that spans at least 50contiguous amino acids of the target polypeptide.

For example, using the computer algorithm GAP (Genetics Computer Group,University of Wisconsin, Madison, Wis.), two polypeptides for which thepercent sequence identity is to be determined are aligned for optimalmatching of their respective amino acids (the “matched span”, asdetermined by the algorithm). A gap opening penalty (which is calculatedas 3× the average diagonal; the “average diagonal” is the average of thediagonal of the comparison matrix being used; the “diagonal” is thescore or number assigned to each perfect amino acid match by theparticular comparison matrix) and a gap extension penalty (which isusually 1/10 times the gap opening penalty), as well as a comparisonmatrix such as PAM 250 or BLOSUM 62 are used in conjunction with thealgorithm. A standard comparison matrix (see Dayhoff et al., Atlas ofProtein Sequence and Structure, 5(3)(1978) for the PAM 250 comparisonmatrix; Henikoff et al., Proc. Natl. Acad. Sci USA, 89:10915-10919(1992) for the BLOSUM 62 comparison matrix) is also used by thealgorithm.

Preferred parameters for a polypeptide sequence comparison include thefollowing:

-   -   Algorithm: Needleman et al., J. Mol. Biol., 48:443-453 (1970);    -   Comparison matrix: BLOSUM 62 from Henikoff et al., supra (1992);    -   Gap Penalty: 12    -   Gap Length Penalty: 4    -   Threshold of Similarity: 0

The GAP program is useful with the above parameters. The aforementionedparameters are the default parameters for polypeptide comparisons (alongwith no penalty for end gaps) using the GAP algorithm.

Preferred parameters for nucleic acid molecule sequence comparisonsinclude the following:

-   -   Algorithm: Needleman et al., supra (1970);    -   Comparison matrix: matches=+10, mismatch=0    -   Gap Penalty: 50    -   Gap Length Penalty: 3

The GAP program is also useful with the above parameters. Theaforementioned parameters are the default parameters for nucleic acidmolecule comparisons.

Other exemplary algorithms, gap opening penalties, gap extensionpenalties, comparison matrices, thresholds of similarity, etc. may beused by those of skill in the art, including those set forth in theProgram Manual, Wisconsin Package, Version 9, September, 1997. Theparticular choices to be made will be apparent to those of skill in theart and will depend on the specific comparison to be made, such asDNA-to-DNA, protein-to-protein, protein-to-DNA; and additionally,whether the comparison is between given pairs of sequences (in whichcase GAP or BestFit are generally preferred) or between one sequence anda large database of sequences (in which case FASTA or BLASTA arepreferred).

Synthesis

It will be appreciated by those skilled in the art that the nucleic acidand polypeptide molecules described herein may be produced byrecombinant and other means.

Nucleic Acid Molecules

The nucleic acid molecules encode a polypeptide comprising the aminoacid sequence of an MK61 polypeptide and can readily be obtained in avariety of ways including, without limitation, chemical synthesis, cDNAor genomic library screening, expression library screening and/or PCRamplification of cDNA.

Recombinant DNA methods used herein are generally those set forth inSambrook et al., Molecular Cloning: A Laboratory Manual, Cold SpringHarbor Laboratory Press, Cold Spring Harbor, N.Y. (1989), and/or Ausubelet al., eds., Current Protocols in Molecular Biology, Green PublishersInc. and Wiley and Sons, NY (1994). The present invention provides fornucleic acid molecules as described herein and methods for obtainingsuch molecules.

Where a gene encoding the amino acid sequence of an MK61 polypeptide hasbeen identified from one species, all or a portion of that gene may beused as a probe to identify orthologs or related genes from the samespecies. The probes or primers may be used to screen cDNA libraries fromvarious tissue sources believed to express the MK61 polypeptide. Inaddition, part or all of a nucleic acid molecule having the sequence asset forth in SEQ ID NO:1, SEQ ID NO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ IDNO:9, SEQ ID NO:11, SEQ ID NO:13, or SEQ ID NO:15 may be used to screena genomic library to identify and isolate a gene encoding the amino acidsequence of an MK61 polypeptide. Typically, conditions of moderate orhigh stringency will be employed for screening to minimize the number offalse positives obtained from the screening.

Nucleic acid molecules encoding the amino acid sequence of MK61polypeptides may also be identified by expression cloning which employsthe detection of positive clones based upon a property of the expressedprotein. Typically, nucleic acid libraries are screened by the bindingof an antibody or other binding partner (e.g., receptor or ligand) tocloned proteins which are expressed and displayed on a host cellsurface. The antibody or binding partner is modified with a detectablelabel to identify those cells expressing the desired clone.

Recombinant expression techniques conducted in accordance with thedescriptions set forth below may be followed to produce thesepolynucleotides and to express the encoded polypeptides. For example, byinserting a nucleic acid sequence which encodes the amino acid sequenceof an MK61 polypeptide into an appropriate vector, one skilled in theart can readily produce large quantities of the desired nucleotidesequence. The sequences can then be used to generate detection probes oramplification primers. Alternatively, a polynucleotide encoding theamino acid sequence of an MK61 polypeptide can be inserted into anexpression vector. By introducing the expression vector into anappropriate host, the encoded MK61 polypeptide may be produced in largeamounts.

Another method for obtaining a suitable nucleic acid sequence is thepolymerase chain reaction (PCR). In this method, cDNA is prepared frompoly(A)+ RNA or total RNA using the enzyme reverse transcriptase. Twooligonucleotide primers, typically complementary to two separate regionsof cDNA (oligonucleotides) encoding the amino acid sequence of an MK61polypeptide, are then added to the cDNA along with a polymerase such asTaq polymerase, and the polymerase amplifies the cDNA region between thetwo primers.

Another means of preparing a nucleic acid molecule encoding the aminoacid sequence of an MK61 polypeptide is chemical synthesis using methodswell known to the skilled artisan, such as those described by Engels etal., Angew. Chem. Intl. Ed., 28:716-734 (1989). These methods include,inter alia, the phosphotriester, phosphoramidite and H-phosphonatemethods for nucleic acid synthesis. A preferred method for such chemicalsynthesis is polymer-supported synthesis using standard phosphoramiditechemistry. Typically, the DNA encoding the amino acid sequence of anMK61 polypeptide will be several hundred nucleotides in length. Nucleicacids larger than about 100 nucleotides can be synthesized as severalfragments using these methods. The fragments can then be ligatedtogether to form the full-length nucleotide sequence of an MK61polypeptide. Usually, the DNA fragment encoding the amino terminus ofthe polypeptide will have an ATG, which encodes a methionine residue.This methionine may or may not be present on the mature form of the MK61polypeptide, depending on whether the polypeptide produced in the hostcell is designed to be secreted from that cell. Other methods known tothe skilled artisan may be used as well.

In certain embodiments, nucleic acid variants contain codons which havebeen altered for the optimal expression of an MK61 polypeptide in agiven host cell. Particular codon alterations will depend upon the MK61polypeptide(s) and host cell(s) selected for expression. Such “codonoptimization” can be carried out by a variety of methods, for example,by selecting codons which are preferred for use in highly expressedgenes in a given host cell. Computer algorithms which incorporate codonfrequency tables such as “Ecohigh.cod” for codon preference of highlyexpressed bacterial genes may be used and are provided by the Universityof Wisconsin Package Version 9.0, Genetics Computer Group, Madison, Wis.Other useful codon frequency tables include “Celegans_high.cod”,“Celegans_low.cod”, “Drosophila_high.cod”, “Human_high.cod”,“Maize_high.cod”, and “Yeast_high.cod”.

Vectors and Host Cells

A nucleic acid molecule encoding the amino acid sequence of an MK61polypeptide may be inserted into an appropriate expression vector usingstandard ligation techniques. The vector is typically selected to befunctional in the particular host cell employed (i.e., the vector iscompatible with the host cell machinery such that amplification of thegene and/or expression of the gene can occur). A nucleic acid moleculeencoding the amino acid sequence of an MK61 polypeptide may beamplified/expressed in prokaryotic, yeast, insect (baculovirus systems),and/or eukaryotic host cells. Selection of the host cell will depend inpart on whether an MK61 polypeptide is to be post-translationallymodified (e.g., glycosylated and/or phosphorylated). If so, yeast,insect, or mammalian host cells are preferable. For a review ofexpression vectors, see Meth. Enz., vol. 185, D. V. Goeddel, ed.,Academic Press Inc., San Diego, Calif. (1990).

Typically, expression vectors used in any of the host cells will containsequences for plasmid maintenance and for cloning and expression ofexogenous nucleotide sequences. Such sequences, collectively referred toas “flanking sequences” in certain embodiments, will typically includeone or more of the following nucleotide sequences: a promoter, one ormore enhancer sequences, an origin of replication, a transcriptionaltermination sequence, a complete intron sequence containing a donor andacceptor splice site, a sequence encoding a leader sequence forpolypeptide secretion, a ribosome binding site, a polyadenylationsequence, a polylinker region for inserting the nucleic acid encodingthe polypeptide to be expressed, and a selectable marker element. Eachof these sequences is discussed below.

Optionally, the vector may contain a “tag”-encoding sequence, i.e., anoligonucleotide molecule located at the 5′ or 3′ end of the MK61polypeptide coding sequence; the oligonucleotide sequence encodespolyHis (such as hexaHis), or another “tag” such as FLAG, HA(hemaglutinin influenza virus) or myc for which commercially availableantibodies exist. This tag is typically fused to the polypeptide uponexpression of the polypeptide, and can serve as a means for affinitypurification of the MK61 polypeptide from the host cell. Affinitypurification can be accomplished, for example, by column chromatographyusing antibodies against the tag as an affinity matrix. Optionally, thetag can subsequently be removed from the purified MK61 polypeptide byvarious means such as using certain peptidases for cleavage.

Flanking sequences may be homologous (i.e., from the same species and/orstrain as the host cell), heterologous (i.e., from a species other thanthe host cell species or strain), hybrid (i.e., a combination offlanking sequences from more than one source) or synthetic, or theflanking sequences may be native sequences which normally function toregulate MK61 polypeptide expression. As such, the source of a flankingsequence may be any prokaryotic or eukaryotic organism, any vertebrateor invertebrate organism, or any plant, provided that the flankingsequence is functional in, and can be activated by, the host cellmachinery.

The flanking sequences useful in the vectors of this invention may beobtained by any of several methods well known in the art. Typically,flanking sequences useful herein other than the endogenous MK61 geneflanking sequences will have been previously identified by mappingand/or by restriction endonuclease digestion and can thus be isolatedfrom the proper tissue source using the appropriate restrictionendonucleases. In some cases, the full nucleotide sequence of a flankingsequence may be known. Here, the flanking sequence may be synthesizedusing the methods described herein for nucleic acid synthesis orcloning.

Where all or only a portion of the flanking sequence is known, it may beobtained using PCR and/or by screening a genomic library with suitableoligonucleotide and/or flanking sequence fragments from the same oranother species. Where the flanking sequence is not known, a fragment ofDNA containing a flanking sequence may be isolated from a larger pieceof DNA that may contain, for example, a coding sequence or even anothergene or genes. Isolation may be accomplished by restriction endonucleasedigestion to produce the proper DNA fragment followed by isolation usingagarose gel purification, Qiagen® column chromatography (Chatsworth,Calif.), or other methods known to the skilled artisan. The selection ofsuitable enzymes to accomplish this purpose will be readily apparent toone of ordinary skill in the art.

An origin of replication is typically a part of those prokaryoticexpression vectors purchased commercially, and the origin aids in theamplification of the vector in a host cell. Amplification of the vectorto a certain copy number can, in some cases, be important for theoptimal expression of an MK61 polypeptide. If the vector of choice doesnot contain an origin of replication site, one may be chemicallysynthesized based on a known sequence, and ligated into the vector. Forexample, the origin of replication from the plasmid pBR322 (Product No.303-3s, New England Biolabs, Beverly, Mass.) is suitable for mostgram-negative bacteria, and various origins (e.g., SV40, polyoma,adenovirus, vesicular stomatitus virus (VSV) or papillomaviruses such asHPV or BPV) are useful for cloning vectors in mammalian cells.Generally, the origin of replication component is not needed formammalian expression vectors (for example, the SV40 origin is often usedonly because it contains the early promoter).

A transcription termination sequence is typically located 3′ of the endof a polypeptide coding region and serves to terminate transcription.Usually, a transcription termination sequence in prokaryotic cells is aG−C rich fragment followed by a poly T sequence. While the sequence iseasily cloned from a library or even purchased commercially as part of avector, it can also be readily synthesized using methods for nucleicacid synthesis such as those described herein.

A selectable marker gene element encodes a protein necessary for thesurvival and growth of a host cell grown in a selective culture medium.Typical selection marker genes encode proteins that (a) conferresistance to antibiotics or other toxins, e.g., ampicillin,tetracycline, or kanamycin for prokaryotic host cells, (b) complementauxotrophic deficiencies of the cell; or (c) supply critical nutrientsnot available from complex media. Preferred selectable markers are thekanamycin resistance gene, the ampicillin resistance gene, and thetetracycline resistance gene. A neomycin resistance gene may also beused for selection in prokaryotic and eukaryotic host cells.

Other selection genes may be used to amplify the gene which will beexpressed. Amplification is the process wherein genes which are ingreater demand for the production of a protein critical for growth arereiterated in tandem within the chromosomes of successive generations ofrecombinant cells. Examples of suitable selectable markers for mammaliancells include dihydrofolate reductase (DHFR) and thymidine kinase. Themammalian cell transformants are placed under selection pressure whichonly the transformants are uniquely adapted to survive by virtue of theselection gene present in the vector. Selection pressure is imposed byculturing the transformed cells under conditions in which theconcentration of selection agent in the medium is successively changed,thereby leading to the amplification of both the selection gene and theDNA that encodes an MK61 polypeptide. As a result, increased quantitiesof MK61 polypeptide are synthesized from the amplified DNA.

A ribosome binding site is usually necessary for translation initiationof mRNA and is characterized by a Shine-Dalgarno sequence (prokaryotes)or a Kozak sequence (eukaryotes). The element is typically located 3′ tothe promoter and 5′ to the coding sequence of an MK61 polypeptide to beexpressed. The Shine-Dalgarno sequence is varied but is typically apolypurine (i.e., having a high A-G content). Many Shine-Dalgarnosequences have been identified, each of which can be readily synthesizedusing methods set forth herein and used in a prokaryotic vector.

A leader, or signal, sequence may be used to direct an MK61 polypeptideout of the host cell. Typically, a nucleotide sequence encoding thesignal sequence is positioned in the coding region of an MK61 nucleicacid molecule, or directly at the 5′ end of an MK61 polypeptide codingregion. Many signal sequences have been identified, and any of thosethat are functional in the selected host cell may be used in conjunctionwith an MK61 nucleic acid molecule. Therefore, a signal sequence may behomologous (naturally occurring) or heterologous to an MK61 gene orcDNA. Additionally, a signal sequence may be chemically synthesizedusing methods described herein. In most cases, the secretion of an MK61polypeptide from the host cell via the presence of a signal peptide willresult in the removal of the signal peptide from the secreted MK61polypeptide. The signal sequence may be a component of the vector, or itmay be a part of an MK61 nucleic acid molecule that is inserted into thevector.

Included within the scope of this invention is the use of either anucleotide sequence encoding a native MK61 polypeptide signal sequencejoined to an MK61 polypeptide coding region or a nucleotide sequenceencoding a heterologous signal sequence joined to an MK61 polypeptidecoding region. The heterologous signal sequence selected should be onethat is recognized and processed, i.e., cleaved by a signal peptidase,by the host cell. For prokaryotic host cells that do not recognize andprocess the native MK61 polypeptide signal sequence, the signal sequenceis substituted by a prokaryotic signal sequence selected, for example,from the group of the alkaline phosphatase, penicillinase, orheat-stable enterotoxin II leaders. For yeast secretion, the native MK61polypeptide signal sequence may be substituted by the yeast invertase,alpha factor, or acid phosphatase leaders. In mammalian cell expressionthe native signal sequence is satisfactory, although other mammaliansignal sequences may be used.

In some cases, such as where glycosylation is desired in a eukaryotichost cell expression system, one may manipulate the various presequencesto improve glycosylation or yield. For example, one may alter thepeptidase cleavage site of a particular signal peptide, or addpresequences, which also may affect glycosylation. The final proteinproduct may have, in the −1 position (relative to the first amino acidof the mature protein), one or more additional amino acids incident toexpression which may not have been totally removed. For example, thefinal protein product may have one or two amino acid residues found inthe peptidase cleavage site, attached to the N-terminus. Alternatively,use of some enzyme cleavage sites may result in a slightly truncatedform of the desired MK61 polypeptide, if the enzyme cuts at such areawithin the mature polypeptide.

In many cases, transcription of a nucleic acid molecule is increased bythe presence of one or more introns in the vector; this is particularlytrue where a polypeptide is produced in eukaryotic host cells,especially mammalian host cells. The introns used may be naturallyoccurring within the MK61 gene, especially where the gene used is a fulllength genomic sequence or a fragment thereof. Where the intron is notnaturally occurring within the gene (as for most cDNAs), the intron(s)may be obtained from another source. The position of the intron withrespect to flanking sequences and the MK61 gene is generally important,as the intron must be transcribed to be effective. Thus, when an MK61cDNA molecule is being transcribed, the preferred position for theintron is 3′ to the transcription start site, and 5′ to the polyAtranscription termination sequence. Preferably, the intron or intronswill be located on one side or the other (i.e., 5′ or 3′) of the cDNAsuch that it does not interrupt the coding sequence. Any intron from anysource, including viral, prokaryotic and eukaryotic (plant or animal)organisms, may be used to practice this invention, provided that it iscompatible with the host cell(s) into which it is inserted. Alsoincluded herein are synthetic introns. Optionally, more than one intronmay be used in the vector.

The expression and cloning vectors of the present invention will eachtypically contain a promoter that is recognized by the host organism andoperably linked to the molecule encoding an MK61 polypeptide. Promotersare untranscribed sequences typically located upstream (5′) to the startcodon of a structural gene (generally within about 100 to 1000 bp) thatcontrol the transcription of the structural gene. Promoters areconventionally grouped into one of two classes, inducible promoters andconstitutive promoters. In this context, inducible promoters includerepressible/depressible promoters and conventional inducible promoters.Inducible promoters initiate increased levels of transcription from DNAunder their control in response to some change in culture conditions,such as the presence or absence of a nutrient or a change intemperature. Constitutive promoters, on the other hand, initiatecontinual gene product production; that is, there is little or nocontrol over gene expression. A large number of promoters, recognized bya variety of potential host cells, are well known. A suitable promoteris operably linked to the DNA encoding an MK61 polypeptide by, e.g.,removing the promoter from the source DNA by restriction enzymedigestion and inserting the desired promoter sequence into the vector.The native MK61 gene promoter sequence may be used to directamplification and/or expression of an MK61 nucleic acid molecule. Aheterologous promoter is preferred, however, if it permits greatertranscription and higher yields of the expressed protein as compared tothe native promoter, and if it is compatible with the host cell systemthat has been selected for use.

Promoters suitable for use with prokaryotic hosts include thebeta-lactamase and lactose promoter systems; alkaline phosphatase, atryptophan (trp) promoter system; and hybrid promoters such as the tacpromoter. Other known bacterial promoters are also suitable. Theirsequences have been published, thereby enabling one skilled in the artto ligate them to the desired DNA sequence(s), using linkers or adaptersas needed to supply any useful restriction sites.

Suitable promoters for use with yeast hosts are also well known in theart. Yeast enhancers are advantageously used with yeast promoters.Suitable promoters for use with mammalian host cells are well known andinclude, but are not limited to, those obtained from the genomes ofviruses such as polyoma virus, fowl pox virus, adenovirus (such asAdenovirus 2), bovine papilloma virus, avian sarcoma virus,cytomegalovirus (CMV), a retrovirus, hepatitis-B virus and mostpreferably Simian Virus 40 (SV40). Other suitable mammalian promotersinclude heterologous mammalian promoters, e.g., heat-shock promoters andthe actin promoter.

Additional promoters which may be of interest in controlling MK61 genetranscription include, but are not limited to: the SV40 early promoterregion (Bernoist and Chambon, Nature, 290:304-310, (1981)), the CMVpromoter, the promoter contained in the 3′ long terminal repeat of Roussarcoma virus (Yamamoto et al., Cell, 22:787-797, (1980)); the herpesthymidine kinase promoter (Wagner et al., Proc. Natl. Acad. Sci. USA,78:144-145, (1981)), the regulatory sequences of the metallothioninegene (Brinster et al., Nature, 296:39-42, (1982)), prokaryoticexpression vectors such as the beta-lactamase promoter (Villa-Kamaroff,et al., Proc. Natl. Acad. Sci. USA, 75:3727-3731, (1978)), or the tacpromoter (DeBoer, et al., Proc. Natl. Acad. Sci. USA, 80:21-25, (1983)).Also of interest are the following animal transcriptional controlregions, which exhibit tissue specificity and have been utilized intransgenic animals: the elastase I gene control region which is activein pancreatic acinar cells [Swift et al., Cell, 38:639-646, (1984);Ornitz et al., Cold Spring Harbor Symp. Quant. Biol., 50:399-409 (1986);MacDonald, Hepatology, 7:425-515, (1987)]; the insulin gene controlregion which is active in pancreatic beta cells (Hanahan, Nature,315:115-122, (1985)); the immunoglobulin gene control region which isactive in lymphoid cells (Grosschedl et al., Cell, 38:647-658 (1984));Adames et al., Nature, 318:533-538 (1985)); (Alexander et al., Mol.Cell. Biol., 7:1436-1444, (1987)); the mouse mammary tumor virus controlregion which is active in testicular, breast, lymphoid and mast cells(Leder et al., Cell, 45:485-495, (1986) ); the albumin gene controlregion which is active in liver (Pinkert et al., Genes and Devel.,1:268-276, (1987)); the alphafetoprotein gene control region which isactive in liver (Krumlauf et al., Mol. Cell. Biol., 5:1639-1648,(1985)); Hammer et al., Science, 235:53-58, (1987)); the alpha1-antitrypsin gene control region which is active in the liver (Kelseyet al., Genes and Devel., 1:161-171, (1987)); the beta-globin genecontrol region which is active in myeloid cells [Mogram et al., Nature,315:338-340, (1985); Kollias et al., Cell, 46:89-94, (1986)]; the myelinbasic protein gene control region which is active in oligodendrocytecells in the brain (Readhead et al., Cell, 48:703-712, (1987)); themyosin light chain-2 gene control region which is active in skeletalmuscle (Sani, Nature, 314:283-286, (1985)); and the gonadotropicreleasing hormone gene control region which is active in thehypothalamus (Mason et al., Science, 234:1372-1378, (1986)).

An enhancer sequence may be inserted into the vector to increase thetranscription of a DNA encoding an MK61 polypeptide of the presentinvention by higher eukaryotes. Enhancers are cis-acting elements ofDNA, usually about 10-300 bp in length, that act on the promoter toincrease its transcription. Enhancers are relatively orientation andposition independent. They have been found 5′ and 3′ to thetranscription unit. Several enhancer sequences available from mammaliangenes are known (e.g., globin, elastase, albumin, alpha-feto-protein andinsulin). Typically, however, an enhancer from a virus will be used. TheSV40 enhancer, the cytomegalovirus early promoter enhancer, the polyomaenhancer, and adenovirus enhancers are exemplary enhancing elements forthe activation of eukaryotic promoters. While an enhancer may be splicedinto the vector at a position 5′ or 3′ to an MK61 nucleic acid molecule,it is typically located at a site 5′ from the promoter.

Expression vectors of the invention may be constructed from a startingvector such as a commercially available vector. Such vectors may or maynot contain all of the desired flanking sequences. Where one or more ofthe desired flanking sequences are not already present in the vector,they may be individually obtained and ligated into the vector. Methodsused for obtaining each of the flanking sequences are well known to oneskilled in the art.

Preferred vectors for practicing this invention are those which arecompatible with bacterial, insect, and mammalian host cells. Suchvectors include, inter alia, pCRII, pCR3, and pcDNA3.1 (InvitrogenCompany, Carlsbad, Calif.), pBSII (Stratagene Company, La Jolla,Calif.), pET15β (Novagen, Madison, Wis.), pGEX (Pharmacia Biotech,Piscataway, N.J.), pEGFP-N2 (Clontech, Palo Alto, Calif.), PETL(BlueBacII; Invitrogen), pDSR-alpha (PCT Publication No. WO 90/14363)and pFastBacDual (Gibco/BRL, Grand Island, N.Y.

Additional suitable vectors include, but are not limited to, cosmids,plasmids or modified viruses, but it will be appreciated that the vectorsystem must be compatible with the selected host cell. Such vectorsinclude, but are not limited to, plasmids such as Bluescript® plasmidderivatives (a high copy number ColE1-based phagemid, Stratagene CloningSystems Inc., La Jolla Calif.), PCR cloning plasmids designed forcloning Taq-amplified PCR products (e.g., TOPO™ TA Cloning® Kit, PCR2.1®plasmid derivatives, Invitrogen, Carlsbad, Calif.), and mammalian,yeast, or virus vectors such as a baculovirus expression system (pBacPAKplasmid derivatives, Clontech, Palo Alto, Calif.).

After the vector has been constructed and a nucleic acid moleculeencoding an MK61 polypeptide has been inserted into the proper site ofthe vector, the completed vector may be inserted into a suitable hostcell for amplification and/or polypeptide expression. The transformationof an expression vector for an MK61 polypeptide into a selected hostcell may be accomplished by well-known methods such as transfection,infection, calcium chloride-mediated transformation, electroporation,microinjection, lipofection or the DEAE-dextran method or other knowntechniques. The method selected will in part be a function of the typeof host cell to be used. These methods and other suitable methods arewell known to the skilled artisan and are set forth, for example, inSambrook et al., supra.

Host cells may be prokaryotic host cells (such as E. coli) or eukaryotichost cells (such as yeast, an insect or vertebrate cells). The hostcell, when cultured under appropriate conditions, may synthesizes anMK61 polypeptide which can subsequently be collected from the culturemedium (if the host cell secretes it into the medium) or directly fromthe host cell producing it (if it is not secreted). The selection of anappropriate host cell will depend upon various factors, such as desiredexpression levels, polypeptide modifications that are desirable ornecessary for activity (such as glycosylation or phosphorylation), andease of folding into a biologically active molecule.

A number of suitable host cells are known in the art and many areavailable from the American Type Culture Collection (ATCC), 10801University Boulevard, Manassas, Va. 20110-2209. Examples include, butare not limited to, mammalian cells, such as Chinese hamster ovary cells(CHO) (ATCC No. CCL61); CHO DHFR-cells (Urlaub et al., Proc. Natl. Acad.Sci. USA, 97:4216-4220 (1980)); human embryonic kidney (HEK) 293 or 293Tcells (ATCC No. CRL1573); or 3T3 cells (ATCC No. CCL92). The selectionof suitable mammalian host cells and methods for transformation,culture, amplification, screening, product production and purificationare known in the art. Other suitable mammalian cell lines are the monkeyCOS-1 (ATCC No. CRL1650) and COS-7 (ATCC No. CRL1651) cell lines, andthe CV-1 cell line (ATCC No. CCL70). Further exemplary mammalian hostcells include primate cell lines and rodent cell lines, includingtransformed cell lines. Normal diploid cells, cell strains derived fromin vitro culture of primary tissue, as well as primary explants, arealso suitable. Candidate cells may be genotypically deficient in theselection gene, or may contain a dominant acting selection gene. Othersuitable mammalian cell lines include, but are not limited to, mouseneuroblastoma N2A cells, HeLa, mouse L-929 cells, 3T3 lines derived fromSwiss, Balb-c or NIH mice, BHK or HaK hamster cell lines, which are alsoavailable from the ATCC. Each of these cell lines is known by andavailable to those skilled in the art of protein expression.

Similarly useful as host cells suitable for the present invention arebacterial cells. For example, the various strains of E. coli (e.g.,HB101, (ATCC No. 33694) DH5α, DH10 and MC1061 (ATCC No. 53338)) are wellknown as host cells in the field of biotechnology. Various strains of B.subtilis, Pseudomonas spp., other Bacillus spp., Streptomyces spp., andthe like may also be employed in this method.

Many strains of yeast cells known to those skilled in the art are alsoavailable as host cells for expression of the polypeptides of thepresent invention. Preferred yeast cells include, for example,Saccharomyces cerivisae and Pichia pastoris.

Additionally, where desired, insect cell systems may be utilized in themethods of the present invention. Such systems are described for examplein Kitts et al., Biotechniques, 14:810-817 (1993); Lucklow, Curr. Opin.Biotechnol., 4:564-572 (1993); and Lucklow et al., J. Virol.,67:4566-4579 (1993). Preferred insect cells are Sf-9 and Hi5(Invitrogen, Carlsbad, Calif.).

One may also use transgenic animals to express glycosylated MK61polypeptides. For example, one may use a transgenic milk-producinganimal (a cow or goat, for example) and obtain the present glycosylatedpolypeptide in the animal milk. One may also use plants to produce MK61polypeptides; however, in general, the glycosylation occurring in plantsis different from that produced in mammalian cells, and may result in aglycosylated product which is not suitable for human therapeutic use.

Polypeptide Production

Host cells comprising an MK61 polypeptide expression vector may becultured using standard media well known to the skilled artisan. Themedia will usually contain all nutrients necessary for the growth andsurvival of the cells. Suitable media for culturing E. coli cellsinclude, for example, Luria Broth (LB) and/or Terrific Broth (TB).Suitable media for culturing eukaryotic cells include Roswell ParkMemorial Institute medium 1640 (RPMI 1640), Minimal Essential Medium(MEM) and/or Dulbecco's Modified Eagle Medium (DMEM), all of which maybe supplemented with serum and/or growth factors as indicated by theparticular cell line being cultured. A suitable medium for insectcultures is Grace's medium supplemented with yeastolate, lactalbuminhydrolysate and/or fetal calf serum, as necessary.

Typically, an antibiotic or other compound useful for selective growthof transformed cells is added as a supplement to the media. The compoundto be used will be dictated by the selectable marker element present onthe plasmid with which the host cell was transformed. For example, wherethe selectable marker element is kanamycin resistance, the compoundadded to the culture medium will be kanamycin. Other compounds forselective growth include ampicillin, tetracycline and neomycin.

The amount of an MK61 polypeptide produced by a host cell can beevaluated using standard methods known in the art. Such methods include,without limitation, Western blot analysis, SDS-polyacrylamide gelelectrophoresis, non-denaturing gel electrophoresis, chromatographicseparation such as Hgh Performance Liquid Chromatography (HPLC),immunodetection such as immunoprecipitation, and/or activity assays suchas DNA binding gel shift assays.

If an MK61 polypeptide has been designed to be secreted from the hostcells, the majority of polypeptide may be found in the cell culturemedium. If however, the MK61 polypeptide is not secreted from the hostcells, it will be present in the cytoplasm and/or the nucleus (foreukaryotic host cells) or in the cytosol (for bacterial host cells).

For an MK61 polypeptide situated in the host cell cytoplasm and/or thenucleus (for eukaryotic host cells) or in the cytosol (for bacterialhost cells), intracellular material (including inclusion bodies forgram-negative bacteria) can be extracted from the host cell using anystandard technique known to the skilled artisan. For example, the hostcells can be lysed to release the contents of the periplasm/cytoplasm byosmotic shock French press, homogenization, enzymatic disruption,exposure to detergents or chaotropes, and/or sonication followed bycentrifugation.

If an MK61 polypeptide has formed inclusion bodies in the cytosol, theinclusion bodies can often bind to the inner and/or outer cellularmembranes and thus will be found primarily in the pellet material aftercentrifugation. The pellet material can then be treated at pH extremesor with a chaotropic agent such as a detergent, guanidine, guanidinederivatives, urea, or urea derivatives in the presence of a reducingagent such as dithiothreitol at alkaline pH or tris carboxyethylphosphine at acid pH to release, break apart, and solubilize theinclusion bodies. The MK61 polypeptide in its now soluble form can thenbe analyzed using gel electrophoresis, immunoprecipitation or the like.If it is desired to isolate the MK61 polypeptide, isolation may beaccomplished using standard methods such as those described herein andin Marston et al., Meth. Enz., 182:264-275 (1990).

In some cases, an MK61 polypeptide may not be biologically active uponisolation. Various methods for “refolding” or converting the polypeptideto its tertiary structure and generating disulfide linkages can be usedto restore biological activity. Such methods include exposing thesolubilized polypeptide to a pH usually above 7 and in the presence of aparticular concentration of a chaotrope. The selection of chaotrope isvery similar to the choices used for inclusion body solubilization, butusually the chaotrope is used at a lower concentration and is notnecessarily the same as chaotropes used for the solubilization. In mostcases the refolding/oxidation solution will also contain a reducingagent or the reducing agent plus its oxidized form in a specific ratioto generate a particular redox potential allowing for disulfideshuffling to occur in the formation of the protein's cysteine bridge(s).Some of the commonly used redox couples include cysteine/cystamine,glutathione (GSH)/dithiobis GSH, cuprous chloride,dithiothreitol(DTT)/dithiane DTT, and2-2mercaptoethanol(bME)/dithio-b(ME). A cosolvent may be used toincrease the efficiency of the refolding, and the more common reagentsused for this purpose include glycerol, polyethylene glycol of variousmolecular weights, arginine and the like.

If inclusion bodies are not formed to a significant degree uponexpression of an MK61 polypeptide, then the polypeptide will be foundprimarily in the supernatant after centrifugation of the cellhomogenate. The polypeptide may be further isolated from the supernatantusing methods such as those described herein or otherwise known in theart.

The purification of an MK61 polypeptide from solution can beaccomplished using a variety of techniques. If the polypeptide has beensynthesized such that it contains a tag such as Hexahistidine (MK61polypeptide/hexaHis) or other small peptide such as FLAG (Eastman KodakCo., New Haven, Conn.) or myc (Invitrogen, Carlsbad, Calif.) at eitherits carboxyl or amino terminus, it may be purified in a one-step processby passing the solution through an affinity column where the columnmatrix has a high affinity for the tag.

For example, polyhistidine binds with great affinity and specificity tonickel; thus an affinity column of nickel (such as the Qiagen® nickelcolumns) can be used for purification of MK61 polypeptide/polyHis. Seefor example, Ausubel et al., eds., Current Protocols in MolecularBiology, Section 10.11.8, John Wiley & Sons, New York (1993).

Additionally, the MK61 polypeptide may be purified through use of amonoclonal antibody which is capable of specifically recognizing andbinding to the MK61 polypeptide.

Suitable procedures for purification thus include, without limitation,affinity chromatography, immunoaffinity chromatography, ion exchangechromatography, molecular sieve chromatography, High Performance LiquidChromatography (HPLC), electrophoresis (including native gelelectrophoresis) followed by gel elution, and preparative isoelectricfocusing (“Isoprime” machine/technique, Hoefer Scientific, SanFrancisco, Calif.). In some cases, two or more purification techniquesmay be combined to achieve increased purity.

MK61 polypeptides may also be prepared by chemical synthesis methods(such as solid phase peptide synthesis) using techniques known in theart, such as those set forth by Merrifield et al., J. Am. Chem. Soc.,85:2149 (1963), Houghten et al., Proc. Natl. Acad. Sci. USA, 82:5132(1985), and Stewart and Young, “Solid Phase Peptide Synthesis”, PierceChemical Co., Rockford, Ill. (1984). Such polypeptides may besynthesized with or without a methionine on the amino terminus.Chemically synthesized MK61 polypeptides may be oxidized using methodsset forth in these references to form disulfide bridges. Chemicallysynthesized MK61 polypeptides are expected to have comparable biologicalactivity to the corresponding MK61 polypeptides produced recombinantlyor purified from natural sources, and thus may be used interchangeablywith a recombinant or natural MK61 polypeptide.

Another means of obtaining an MK61 polypeptide is via purification frombiological samples such as source tissues and/or fluids in which theMK61 polypeptide is naturally found. Such purification can be conductedusing methods for protein purification as described herein or asotherwise known in the art. The presence of the MK61 polypeptide duringpurification may be monitored, for example, using an antibody preparedagainst recombinantly produced MK61 polypeptide or peptide fragmentsthereof.

A number of additional methods for producing nucleic acids andpolypeptides are known in the art, and the methods can be used toproduce polypeptides having specificity for MK61. See for example,Roberts et al., Proc. Natl. Acad. Sci. USA, 94:12297-12303 (1997), whichdescribes the production of fusion proteins between an mRNA and itsencoded peptide. See also Roberts, R., Curr. Opin. Chem. Biol.,3:268-273 (1999). Additionally, U.S. Pat. No. 5,824,469 describesmethods of obtaining oligonucleotides capable of carrying out a specificbiological function. The procedure involves generating a heterogeneouspool of oligonucleotides, each having a 5′ randomized sequence, acentral preselected sequence, and a 3′ randomized sequence. Theresulting heterogeneous pool is introduced into a population of cellsthat do not exhibit the desired biological function. Subpopulations ofthe cells are then screened for those which exhibit a predeterminedbiological function. From that subpopulation, oligonucleotides capableof carrying out the desired biological function are isolated.

U.S. Pat. Nos. 5,763,192, 5,814,476, 5,723,323 and 5,817,483 describeprocesses for producing peptides or polypeptides. This is done byproducing stochastic genes or fragments thereof, and then introducingthese genes into host cells which produce one or more proteins encodedby the stochastic genes. The host cells are then screened to identifythose clones producing peptides or polypeptides having the desiredactivity.

Another method for producing peptides or polypeptides is described inPCT/US98/20094 (WO99/15650) filed by Athersys, Inc. Known as “RandomActivation of Gene Expression for Gene Discovery” (RAGE-GD), the processinvolves the activation of endogenous gene expression or over-expressionof a gene by in situ recombination methods. For example, expression ofan endogenous gene is activated or increased by integrating a regulatorysequence into the target cell which is capable of activating expressionof the gene by non-homologous or illegitimate recombination. The targetDNA is first subjected to radiation, and a genetic promoter inserted.The promoter randomly locates a break at the front 5′ end of a gene,initiating transcription of the gene. This results in expression of thedesired peptide or polypeptide.

It will be appreciated that these methods can also be used to createcomprehensive IL-17 like protein expression libraries, which cansubsequently be used for high throughput phenotypic screening in avariety of assays, such as biochemical assays, cellular assays, andwhole organism assays (e.g., plant, mouse, etc.).

Chemical Derivatives

Chemically modified derivatives of the MK61 polypeptides may be preparedby one skilled in the art, given the disclosures set forth hereinbelow.MK61 polypeptide derivatives are modified in a manner that is differenteither in the type or location of the molecules naturally attached tothe polypeptide. Derivatives may include molecules formed by thedeletion of one or more naturally-attached chemical groups. Thepolypeptide comprising the amino acid sequence of SEQ ID NO:2, SEQ IDNO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16, or an MK61 polypeptide variant, may be modifiedby the covalent attachment of one or more polymers. For example, thepolymer selected is typically water soluble so that the protein to whichit is attached does not precipitate in an aqueous environment, such as aphysiological environment. Included within the scope of suitablepolymers is a mixture of polymers. Preferably, for therapeutic use ofthe end-product preparation, the polymer will be pharmaceuticallyacceptable.

The polymers each may be of any molecular weight and may be branched orunbranched. The polymers each typically have an average molecular weightof between about 2 kDa to about 100 kDa (the term “about” indicatingthat in preparations of a water soluble polymer, some molecules willweigh more, some less, than the stated molecular weight). The averagemolecular weight of each polymer is preferably between about 5 kDa,about 50 kDa, more preferably between about 12 kDa to about 40 kDa andmost preferably between about 20 kDa to about 35 kDa.

Suitable water soluble polymers or mixtures thereof include, but are notlimited to, N-linked or O-linked carbohydrates; sugars; phosphates;polyethylene glycol (PEG) (including the forms of PEG that have beenused to derivatize proteins, including mono-(C₁-C₁₀) alkoxy- oraryloxy-polyethylene glycol); monomethoxy-polyethylene glycol; dextran(such as low molecular weight dextran of, for example, about 6 kDa);,cellulose; or other carbohydrate-based polymers, poly-(N-vinylpyrrolidone) polyethylene glycol, propylene glycol homopolymers, apolypropylene oxide/ethylene oxide co-polymer, polyoxyethylated polyols(e.g., glycerol) and polyvinyl alcohol. Also encompassed by the presentinvention are bifunctional crosslinking molecules which may be used toprepare covalently attached multimers of the polypeptide comprising theamino acid sequence of SEQ ID NO:2, SEQ ID NO:4, SEQ ID NO:6, SEQ IDNO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ ID NO:14, or SEQ ID NO:16, or anMK61 polypeptide variant.

In general, chemical derivatization may be performed under any suitablecondition used to react a protein with an activated polymer molecule.Methods for preparing chemical derivatives of polypeptides willgenerally comprise the steps of.(a) reacting the polypeptide with theactivated polymer molecule (such as a reactive ester or aldehydederivative of the polymer molecule) under conditions whereby thepolypeptide comprising the amino acid sequence of SEQ ID NO:2, SEQ IDNO:4, SEQ ID NO:6, SEQ ID NO:8, SEQ ID NO:10, SEQ ID NO:12, SEQ IDNO:14, or SEQ ID NO:16, or an MK61 polypeptide variant becomes attachedto one or more polymer molecules, and (b) obtaining the reactionproduct(s). The optimal reaction conditions will be determined based onknown parameters and the desired result. For example, the larger theratio of polymer molecules:protein, the greater the percentage ofattached polymer molecule. In one embodiment, the MK61 polypeptidederivative may have a single polymer molecule moiety at the aminoterminus (see, for example, U.S. Pat. No. 5,234,784).

The pegylation of the polypeptide may be specifically carried out by anyof the pegylation reactions known in the art, as described for examplein the following references: Francis et al., Focus on Growth Factors,3:4-10 (1992); EP 0154316; EP 0401384 and U.S. Pat. No. 4,179,337. Forexample, pegylation may be carried out via an acylation reaction or analkylation reaction with a reactive polyethylene glycol molecule (or ananalogous reactive water-soluble polymer) as described herein. For theacylation reactions, the polymer(s) selected should have a singlereactive ester group. For reductive alkylation, the polymer(s) selectedshould have a single reactive aldehyde group. A reactive aldehyde is,for example, polyethylene glycol propionaldehyde, which is water stable,or mono C₁-C₁₀ alkoxy or aryloxy derivatives thereof (see U.S. Pat. No.5,252,714).

In another embodiment, MK61 polypeptides may be chemically coupled tobiotin, and the biotin/MK61 polypeptide molecules which are conjugatedare then allowed to bind to avidin, resulting in tetravalentavidin/biotin/MK61 polypeptide molecules. MK61 polypeptides may also becovalently coupled to dinitrophenol (DNP) or trinitrophenol (TNP) andthe resulting conjugates precipitated with anti-DNP or anti-TNP-IgM toform decameric conjugates with a valency of 10.

Generally, conditions which may be alleviated or modulated by theadministration of the present MK61 polypeptide derivatives include thosedescribed herein for MK61 polypeptides. However, the MK61 polypeptidederivatives disclosed herein may have additional activities, enhanced orreduced biological activity, or other characteristics, such as increasedor decreased half-life, as compared to the non-derivatized molecules.

Genetically Engineered Non-Human Animals

Additionally included within the scope of the present invention arenon-human animals such as mice, rats, rabbits, or other rodents,rabbits, goats or sheep, or other farm animals, in which the gene (orgenes) encoding the native MK61 polypeptide has (have) been disrupted(“knocked out”) such that the level of expression of this gene or genesis significantly decreased or completely abolished. Such animals may beprepared using techniques and methods such as those described in U.S.Pat. No. 5,557,032.

The present invention further includes non-human animals such as mice,rats or other rodents, rabbits, goats, sheep, or other farm animals, inwhich either the native form of the MK61 gene(s) for that animal or aheterologous MK61 gene(s) is (are) over-expressed by the animal, therebycreating a “transgenic” animal. Such transgenic animals may be preparedusing well-known methods such as those described in U.S. Pat. No.5,489,743 and PCT Application No. WO94/28122.

The present invention further includes non-human animals in which thepromoter for one or more of the MK61 polypeptides of the presentinvention is either activated or inactivated (e.g., by using homologousrecombination methods) to alter the level of expression of one or moreof the native MK61 polypeptides.

These non-human animals may be used for drug candidate screening. Insuch screening, the impact of a drug candidate on the animal may bemeasured; for example, drug candidates may decrease or increase theexpression of the MK61 gene. In certain embodiments, the amount ofMK61polypeptide that is produced may be measured after the exposure ofthe animal to the drug candidate. Additionally, in certain embodiments,one may detect the actual impact of the drug candidate on the animal.For example, the overexpression of a particular gene may result in, orbe associated with, a disease or pathological condition. In such cases,one may test a drug candidate's ability to decrease expression of thegene or its ability to prevent, inhibit, or eliminate a pathologicalcondition. In other examples, the production of a particular metabolicproduct such as a fragment of a polypeptide, may result in, or beassociated with, a disease or pathological condition. In such cases, onemay test a drug candidate's ability to decrease the production of such ametabolic product or its ability to prevent inhibit, or eliminate apathological condition.

Microarray

It will be appreciated that DNA microarray technology can be utilized inaccordance with the present invention. DNA microarrays are miniature,high density arrays of nucleic acids positioned on a solid support, suchas glass. Each cell or element within the array has numerous copies of asingle species of DNA which acts as a target for hybridization for itscognate mRNA. In expression profiling using DNA microarray technology,mRNA is first extracted from a cell or tissue sample and then convertedenzymatically to fluorescently labeled cDNA. This material is hybridizedto the microarray and unbound cDNA is removed by washing. The expressionof discrete genes represented on the array is then visualized byquantitating the amount of labeled cDNA which is specifically bound toeach target DNA. In this way, the expression of thousands of genes canbe quantitated in a high throughput, parallel manner from a singlesample of biological material.

This high throughput expression profiling has a broad range ofapplications with respect to the MK61 molecules of the invention,including but not limited to: the identification and validation of MK61disease-related genes as targets for therapeutics; molecular toxicologyof MK61 molecules and inhibitors thereof; stratification of populationsand generation of surrogate markers for clinical trials; and theenhancement of an MK61 related small molecule drug discovery by aidingin the identification of selective compounds in high throughput screens(HTS).

Selective Binding Agents

As used herein, the term “selective binding agent” refers to a moleculewhich has specificity for one or more MK61 polypeptides. Suitableselective binding agents include, but are not limited to, antibodies andderivatives thereof, polypeptides, and small molecules. Suitableselective binding agents may be prepared using methods known in the art.An exemplary MK61 polypeptide selective binding agent of the presentinvention is capable of binding a certain portion of the MK61polypeptide thereby inhibiting the binding of the polypeptide to theMK61 polypeptide receptor(s).

Selective binding agents such as antibodies and antibody fragments thatbind MK61 polypeptides are within the scope of the present invention.The antibodies may be polyclonal including monospecific polyclonal,monoclonal (MAbs), recombinant, chimeric, humanized such as CDR-grafted,human, single chain, and/or bispecific, as well as fragments, variantsor derivatives thereof. Antibody fragments include those portions of theantibody which bind to an epitope on the MK61 polypeptide. Examples ofsuch fragments include Fab and F(ab′) fragments generated by enzymaticcleavage of full-length antibodies. Other binding fragments includethose generated by recombinant DNA techniques, such as the expression ofrecombinant plasmids containing nucleic acid sequences encoding antibodyvariable regions.

Polyclonal antibodies directed toward an MK61 polypeptide generally areproduced in animals (e.g., rabbits or mice) by means of multiplesubcutaneous, intramuscular or intraperitoneal injections of MK61polypeptide and an adjuvant. It may be useful to conjugate an MK61polypeptide to a carrier protein that is immunogenic in the species tobe immunized, such as keyhole limpet hemocyanin, serum, albumin, bovinethyroglobulin, or soybean trypsin inhibitor. Also, aggregating agentssuch as alum are used to enhance the immune response. Afterimmunization, the animals are bled and the serum is assayed foranti-MK61 polypeptide antibody titer.

Monoclonal antibodies directed toward an MK61 polypeptide are producedusing any method which provides for the production of antibody moleculesby continuous cell lines in culture. Examples of suitable methods forpreparing monoclonal antibodies include the hybridoma methods of Kohleret al., Nature, 256:495-497 (1975) and the human B-cell hybridomamethod, Kozbor, J. Immunol., 133:3001 (1984) and Brodeur et al.,Monoclonal Antibody Production Techniques and Applications, pp. 51-63(Marcel Dekker, Inc., New York, 1987). Also provided by the inventionare hybridoma cell lines which produce monoclonal antibodies reactivewith MK61 polypeptides.

Monoclonal antibodies of the invention may be modified for use astherapeutics. One embodiment is a “chimeric” antibody in which a portionof the heavy and/or light chain is identical with or homologous to acorresponding sequence in antibodies derived from a particular speciesor belonging to a particular antibody class or subclass, while theremainder of the chain(s) is/are identical with or homologous to acorresponding sequence in antibodies derived from another species orbelonging to another antibody class or subclass. Also included arefragments of such antibodies, so long as they exhibit the desiredbiological activity. See, U.S. Pat. No. 4,816,567 and Morrison et al.,Proc. Natl. Acad. Sci. USA, 81:6851-6855 (1985).

In another embodiment, a monoclonal antibody of the invention is a“humanized” antibody. Methods for humanizing non-human antibodies arewell known in the art (see U.S. Pat. Nos. 5,585,089, and 5,693,762).Generally, a humanized antibody has one or more amino acid residuesintroduced into it from a source which is non-human. Humanization can beperformed, for example, using methods described in the art (Jones etal., Nature 321:522-525 (1986); Riechmann et al., Nature, 332:323-327(1988); Verhoeyen et al., Science 239:1534-1536 (1988)), by substitutingat least a portion of a rodent complementarity-determining region (CDR)for the corresponding regions of a human antibody.

Also encompassed by the invention are human antibodies which bind MK61polypeptides, fragments, variants, and/or derivatives. Using transgenicanimals (e.g., mice) that are capable of producing a repertoire of humanantibodies in the absence of endogenous immunoglobulin production, suchantibodies are produced by immunization with an MK61 antigen (i.e.,having at least 6 contiguous amino acids), optionally conjugated to acarrier. See, for example, Jakobovits et al., Proc. Natl. Acad. Sci. USA, 90:2551-2555 (1993); Jakobovits et al., Nature, 362:255-258 (1993) andBruggermann et al., Year in Immunol., 7:33 (1993). In one method, suchtransgenic animals are produced by incapacitating the endogenous lociencoding the heavy and light immunoglobulin chains therein, andinserting nucleic acids encoding human heavy and light chain proteinsinto the genome thereof. Partially modified animals, that is thosehaving less than the full complement of modifications, are thencross-bred to obtain an animal having all of the desired immune systemmodifications. When administered an immunogen, these transgenic animalsproduce antibodies with human variable regions, including human(ratherthan, e.g., murine) amino acid sequences, including variable regionswhich are immunospecific for these antigens. See PCT application nos.PCT/US96/05928 and PCT/US93/06926. Additional methods are described inU.S. Pat. No. 5,545,807, PCT application nos. PCT/US91/245,PCT/GB89/01207, and in EP 546073B1 and EP 546073A1. Human antibodies mayalso be produced by the expression of recombinant DNA in host cells orby expression in hybridoma cells as described herein.

In an alternative embodiment, human antibodies can be produced fromphage-display libraries (Hoogenboom et al., J. Mol. Biol. 227:381 (1991)and Marks et al., J. Mol. Biol. 222:581 (1991)). These processes mimicimmune identification through the display of antibody repertoires on thesurface of filamentous bacteriophage, and subsequent selection of phageby their binding to an antigen of choice. One such technique isdescribed in PCT Application No. PCT/US98/17364, filed in the amen ofAdams et al. which describes the isolation of high affinity andfunctionally agonistic antibodies for MPL- and msk-receptors using suchan approach.

Chimeric, CDR grafted, and humanized antibodies are typically producedby recombinant methods. Nucleic acids encoding the antibodies areintroduced into host cells and expressed using materials and proceduresdescribed herein or known in the art. In a preferred embodiment, theantibodies are produced in mammalian host cells, such as CHO cells.Monoclonal (e.g., human) antibodies may be produced by the expression ofrecombinant DNA in host cells or by expression in hybridoma cells asdescribed herein.

The anti-MK61 antibodies of the invention may be employed in any knownassay method, such as competitive binding assays, direct and indirectsandwich assays, and immunoprecipitation assays (Sola, MonoclonalAntibodies: A Manual of Techniques, pp. 147-158 (CRC Press, Inc., 1987))for the detection and quantitation of MK61 polypeptides. The antibodieswill bind MK61 polypeptides with an affinity which is appropriate forthe assay method being employed.

For diagnostic applications, in certain embodiments, anti-MK61antibodies may be labeled with a detectable moiety. The detectablemoiety can be any one which is capable of producing, either directly orindirectly, a detectable signal. For example, the detectable moiety maybe a radioisotope, such as ³H, ¹⁴C, ³²P, ³⁵S, or ¹²⁵I; a fluorescent orchemiluminescent compound, such as fluorescein isothiocyanate,rhodamine, or luciferin; or an enzyme, such as alkaline phosphatase,β-galactosidase, or horseradish peroxidase (Bayer et al., Meth. Enz.,184:138-163 (1990)).

Competitive binding assays rely on the ability of a labeled standard(e.g., an MK61 polypeptide, or an immunologically reactive portionthereof) to compete with the test sample analyte (an MK61 polypeptide)for binding with a limited amount of anti-MK61 antibody. The amount ofan MK61 polypeptide in the test sample is inversely proportional to theamount of standard that becomes bound to the antibodies. To facilitatedetermining the amount of standard that becomes bound, the antibodiestypically are insolubilized before or after the competition, so that thestandard and analyte that are bound to the antibodies may convenientlybe separated from the standard and analyte which remain unbound.

Sandwich assays typically involve the use of two antibodies, eachcapable of binding to a different immunogenic portion, or epitope, ofthe protein to be detected and/or quantitated. In a sandwich assay, thetest sample analyte is typically bound by a first antibody which isimmobilized on a solid support, and thereafter a second antibody bindsto the analyte, thus forming an insoluble three-part complex. See, e.g.,U.S. Pat. No. 4,376,110. The second antibody may itself be labeled witha detectable moiety (direct sandwich assays) or may be measured using ananti-immunoglobulin antibody that is labeled with a detectable moiety(indirect sandwich assays). For example, one type of sandwich assay isan enzyme-linked immunosorbent assay (ELISA), in which case thedetectable moiety is an enzyme.

The selective binding agents, including anti-MK61 antibodies, are alsouseful for in vivo imaging. An antibody labeled with a detectable moietymay be administered to an animal, preferably into the bloodstream, andthe presence and location of the labeled antibody in the host isassayed. The antibody may be labeled with any moiety that is detectablein an animal, whether by nuclear magnetic resonance, radiology, or otherdetection means known in the art.

Selective binding agents of the invention, including antibodies, may beused as therapeutics. These therapeutic agents are generally agonists orantagonists in that they either enhance or reduce, respectively, atleast one of the biological activities of an MK61 polypeptide. In oneembodiment, antagonist antibodies of the invention are antibodies orbinding fragments thereof which are capable of specifically binding toan MK61 polypeptide and which are capable of inhibiting or eliminatingthe functional activity of an MK61 polypeptide in vivo or in vitro. Inpreferred embodiments, the selective binding agent, e.g., an antagonistantibody, will inhibit the functional activity of an MK61 polypeptide byat least about 50%, and preferably by at least about 80%. In anotherembodiment, the selective binding agent may be an antibody that iscapable of interacting with an MK61 binding partner (a ligand orreceptor) thereby inhibiting or eliminating MK61 activity in vitro or inviva. Selective binding agents, including agonist and antagonistanti-MK61 antibodies, are identified by screening assays which are wellknown in the art.

The invention also relates to a kit comprising MK61 selective bindingagents (such as antibodies) and other reagents useful for detecting MK61polypeptide levels in biological samples. Such reagents may include adetectable label, blocking serum, positive and negative control samples,and detection reagents.

MK61 polypeptides can be used to clone MK61 ligand(s) using an“expression cloning” strategy. Radiolabeled (¹²⁵Iodine) MK61 polypeptideor “affinity/activity-tagged” MK61 polypeptide (such as an Fc fusion oran alkaline phosphatase fusion) can be used in binding assays toidentify a cell type or a cell line or tissue that expresses MK61ligand(s). RNA isolated from such cells or tissues can then be convertedto cDNA, cloned into a mammalian expression vector, and transfected intomammalian cells (for example, COS, or 293) to create an expressionlibrary. Radiolabeled or tagged MK61 polypeptide can then be used as anaffinity reagent to identify and isolate the subset of cells in thislibrary expressing MK61 ligand(s). DNA is then isolated from these cellsand transfected into mammalian cells to create a secondary expressionlibrary in which the fraction of cells expressing MK61 ligand(s) wouldbe many-fold higher than in the original library. This enrichmentprocess can be repeated iteratively until a single recombinant clonecontaining an MK61 ligand is isolated. Isolation of MK61 ligand(s) isuseful for identifying or developing novel agonists and antagonists ofthe MK61 signaling pathway. Such agonists and antagonists include MK61ligand(s), anti-MK61 ligand antibodies, small molecules or antisenseoligonucleotides. These may be used for treating, preventing, ordiagnosing one or more diseases or disorders, including those describedherein.

Assaying For Other Modulators of MK61 Polypeptide Activity

In some situations, it may be desirable to identify molecules that aremodulators, i.e., agonists or antagonists, of the activity of MK61polypeptide. Natural or synthetic molecules that modulate MK61 likepolypeptide may be identified using one or more screening assays, suchas those described herein. Such molecules may be administered either inan ex vivo manner, or in an in vivo manner by injection, or by oraldelivery, implantation device or the like.

“Test molecule(s)” refers to the molecule(s) that is/are underevaluation for the ability to modulate (i.e., increase or decrease) theactivity of an MK61 polypeptide. Most commonly, a test molecule willinteract directly with an MK61 polypeptide. However, it is alsocontemplated that a test molecule may also modulate MK61 polypeptideactivity indirectly, such as by affecting MK61 gene expression, or bybinding to an MK61 binding partner (e.g., receptor or ligand). In oneembodiment, a test molecule will bind to an MK61 polypeptide with anaffinity constant of at least about 10⁻⁶ M, preferably about 10⁻⁸ M,more preferably about 10⁻⁹ M, and even more preferably about 10⁻¹⁰ M.

Methods for identifying compounds which interact with MK61 polypeptidesare encompassed by the present invention. In certain embodiments, anMK61 polypeptide is incubated with a test molecule under conditionswhich permit the interaction of the test molecule with an MK61polypeptide, and the extent of the interaction can be measured. The testmolecule(s) can be screened in a substantially purified form or in acrude mixture.

In certain embodiments, an MK61 polypeptide agonist or antagonist may bea protein, peptide, carbohydrate, lipid, or small molecular weightmolecule which interacts with MK61 polypeptide to regulate its activity.Molecules which regulate MK61 polypeptide expression include nucleicacids which are complementary to nucleic acids encoding an MK61polypeptide, or are complementary to nucleic acid sequences which director control the expression of MK61 polypeptide, and which act asanti-sense regulators of expression.

Once a set of test molecules has been identified as interacting with anMK61 polypeptide, the molecules may be further evaluated for theirability to increase or decrease MK61 polypeptide activity. Themeasurement of the interaction of test molecules with MK61 polypeptidesmay be carried out in several formats, including cell-based bindingassays, membrane binding assays, solution-phase assays and immunoassays.In general, test molecules are incubated with an MK61 polypeptide for aspecified period of time, and MK61 polypeptide activity is determined byone or more assays for measuring biological activity.

The interaction of test molecules with MK61 polypeptides may also beassayed directly using polyclonal or monoclonal antibodies in animmunoassay. Alternatively, modified forms of MK61 polypeptidescontaining epitope tags as described herein may be used in immunoassays.

In the event that MK61 polypeptides display biological activity throughan interaction with a binding partner (e.g., a receptor or a ligand) areassessed by a variety of in vitro assays may be used to measure thebinding of an MK61 polypeptide to the corresponding binding partner(such as a selective binding agent, receptor or ligand). These assaysare used to screen test molecules for their ability to increase ordecrease the rate and/or the extent of binding of an MK61 polypeptide toits binding partner. In one assay, an MK61 polypeptide is immobilized inthe wells of a microtiter plate. Radiolabeled MK61 binding partner (forexample, iodinated MK61 binding partner) and the test molecule(s) areadded either one at a time (in either order) or simultaneously to thewells. After incubation, the wells are washed and counted (using ascintillation counter) for radioactivity to determine the extent towhich the binding partner bound to MK61 polypeptide. Typically, themolecules will be tested over a range of concentrations, and a series ofcontrol wells lacking one or more elements of the test assays can beused for accuracy in the evaluation of the results. An alternative tothis method involves reversing the “positions” of the proteins, i.e.,immobilizing MK61 binding partner to the microtiter plate wells,incubating with the test molecule and radiolabeled MK61 polypeptide, anddetermining the extent of MK61 polypeptide binding. See, for example,chapter 18, Current Protocols in Molecular Biology, Ausubel et al.,eds., John Wiley & Sons, New York, N.Y. (1995).

As an alternative to radiolabeling, an MK61 polypeptide or its bindingpartner may be conjugated to biotin and the presence of biotinylatedprotein can then be detected using streptavidin linked to an enzyme,such as horseradish peroxidase (HRP) or alkaline phosphatase (AP), isdetected colorometrically or by fluorescent tagging of streptavidin. Anantibody directed to an MK61 polypeptide or to an MK61 binding partnerand conjugated to biotin may also be used and can be detected afterincubation with enzyme-linked streptavidin linked to AP or HRP.

An MK61 polypeptide or an MK61 binding partner can also be immobilizedby attachment to agarose beads, acrylic beads or other types of suchinert solid phase substrates. The substrate-protein complex can beplaced in a solution containing the complementary protein and the testcompound. After incubation the beads is precipitated by centrifugation,and the amount of binding between an MK61 polypeptide and its bindingpartner can be assessed using the methods described herein.Alternatively, the substrate-protein complex is immobilized in a column,and the test molecule and complementary protein are passed through thecolumn. The formation of a complex between an MK61 polypeptide and itsbinding partner is assessed using any of the techniques set forthherein, i.e., radiolabeling, antibody binding or the like.

Another in vitro assay that is useful for identifying a test moleculethat increases or decreases the formation of a complex between an MK61polypeptide and an MK61 binding partner is a surface plasmon resonancedetector system such as the BIAcore assay system (Pharmacia, Piscataway,N.J.). The BIAcore system may be carried out using the manufacturer'sprotocol. This assay essentially involves the covalent binding of eitherMK61 polypeptide or an MK61 binding partner to a dextran-coated sensorchip which is located in a detector. The test compound and the othercomplementary protein can then be injected, either simultaneously orsequentially, into the chamber containing the sensor chip. The amount ofcomplementary protein that binds can be assessed based on the change inmolecular mass which is physically associated with the dextran-coatedside of the sensor chip. The change in molecular mass can be measured bythe detector system.

In some cases, it may be desirable to evaluate two or more testcompounds together for their ability to increase or decrease theformation of a complex between an MK61 polypeptide and an MK61 bindingpartner. In these cases, the assays set forth herein can be readilymodified by adding such additional test compound(s) either simultaneouswith, or subsequent to, the first test compound. The remainder of thesteps in the assay are as set forth herein.

In vitro assays such as those described herein may be usedadvantageously to screen large numbers of compounds for effects oncomplex formation by an MK61 polypeptide and an MK61 binding partner.The assays may be automated to screen compounds generated in phagedisplay, synthetic peptide and chemical synthesis libraries.

Compounds which increase or decrease the formation of a complex betweenan MK61 polypeptide and an MK61 binding partner may also be screened incell culture using cells and cell lines expressing either MK61polypeptide or MK61 binding partner. Cells and cell lines may beobtained from any mammal, but preferably will be from human or otherprimate, canine or rodent sources. The binding of an MK61 polypeptide tocells expressing MK61 binding partner at the surface is evaluated in thepresence or absence of test molecules, and the extent of binding may bedetermined by, for example, flow cytometry using a biotinylated antibodyto an MK61 binding partner. Cell culture assays can be usedadvantageously to further evaluate compounds that score positive inprotein binding assays described herein.

Cell cultures can also be used to screen the impact of a drug candidate.For example, drug candidates may decrease or increase the expression ofthe MK61 gene. In certain embodiments, the amount of MK61 polypeptidethat is produced may be measured after exposure of the cell culture tothe drug candidate. In certain embodiments, one may detect the actualimpact of the drug candidate on the cell culture. For example, theoverexpression of a particular gene may have a particular impact on thecell culture. In such cases, one may test a drug candidate's ability toincrease or decrease the expression of the gene or its ability toprevent or inhibit a particular impact on the cell culture. In otherexamples, the production of a particular metabolic product such as afragment of a polypeptide may result in, or be associated with, adisease or pathological condition. In such cases, one may test a drugcandidate's ability to decrease the production of such a metabolicproduct in a cell culture.

A yeast two-hybrid system (Chien et al., Proc. Natl. Acad. Sci. USA,88:9578-9583 (1991)) can be used to identify novel polypeptides thatbind to, or interact with, MK61 polypeptides. As an example, hybridconstructs comprising DNA encoding a cytoplasmic domain of an MK61polypeptide fused to a yeast GAL4-DNA binding domain may be used as atwo-hybrid bait plasmid. Positive clones emerging from the screening maybe characterized further to identify interacting proteins.

P38 Inhibitors

A new approach to intervention between the extracellular stimulus andthe secretion of IL-1 and TNFα from the cell involves blocking signaltransduction through inhibition of a kinase which lies on the signalpathway. One example is through inhibition of P-38 (also called “RK” or“SAPK-2”, Lee et al., Nature, 372:739 (1994)), a known ser/thr kinase(clone reported in Han et al., Biochimica Biophysica Acta, 1265:224-227(1995)). A linear relationship has been shown for effectiveness in acompetitive binding assay to P-38, and the same inhibitor diminishingthe levels of IL-1 secretion from monocytes following LPS stimulation.Following LPS stimulation of monocytes, the levels of messenger RNA forTNFα have been shown to increase 100 fold, but the protein levels ofTNFα are increased 10,000 fold. Thus, a considerable amplification ofthe TNF signaling occurs at the translational level. Following LPSstimulation of monocytes in the presence of a P-38 inhibitor, the levelsof mRNA are not affected, but the levels of final TNF protein aredramatically reduced (up to 80-90% depending on the effectiveness of theP-38 inhibitor). Thus, the above experiments lend strong support to theconclusion that inhibition of P-38 leads to diminished translationalefficiency. Further evidence that TNFα is under translational control isfound in the deletion experiments of Beutler et al. and Lee, whereinsegments of 3′ untranslated mRNA (3′ UTR) are removed resulting in hightranslational efficiency for TNFα. More importantly, the P-38 inhibitorsdid not have an effect on the level of TNFα (i.e., translationalefficiency) when the appropriate segments of TNFα mRNA are deleted.Thus, the correlative data between the level of binding of inhibitors toP-38 and the diminished IL-1 and TNFα levels following LPS stimulationwith the same inhibitors, plus the above biochemical evidence regardingthe effect of P-38 inhibitors on translational efficiency of both TNFαand IL-1 make a strong cause and effect relationship. The role of P-38in the cell is still being delineated; so therefore, other beneficialeffects regarding inflammatory diseases or other disease states obtainedfrom its inhibition maybe forthcoming.

Elevated levels of TNFα and/or IL-1 may contribute to the onset,etiology, or exacerbate a number of disease states, including, but notlimited to: rheumatoid arthritis; osteoarthritis; rheumatoidspondylitis; gouty arthritis; inflammatory bowel disease; adultrespiratory distress syndrome (ARDS); psoriasis; Crohn's disease;allergic rhinitis; ulcerative colitis; anaphylaxis; contact dermatitis;asthma; antiviral therapy including those viruses sensitive to TNFαinhibition—HIV-1, HIV-2, HIV-3, cytomegalovirus (CMV), influenza,adenovirus, and the herpes viruses including HSV-1, HSV-2, and herpeszoster; muscle degeneration; cachexia; Reiter's syndrome; type IIdiabetes; bone resorption diseases; graft vs. host reaction; ischemiareperfusion injury; atherosclerosis; brain trauma; Alzheimer's disease;multiple sclerosis; cerebral malaria; sepsis; septic shock; toxic shocksyndrome; fever and myalgias due to infection.

Substituted imidazole, pyrrole, pyridine, pyrimidine and the likecompounds have been described for use in the treatment of cytokinemediated diseases by inhibition of proinflammatory cytokines, such asIL-1, IL-6, IL-8, and TNF. Substituted imidazoles for use in thetreatment of cytokine mediated diseases have been described in U.S. Pat.No. 5,593,992; WO93/14081; WO97/18626; WO96/21452; WO96/21654;WO96/40143; WO97/05878; and WO97/05878. Substituted imidazoles for usein the treatment of inflammation has been described in U.S. Pat. No.3,929,807. Substituted pyrrole compounds for use in the treatment ofcytokine mediated diseases have been described in WO97/05877;WO97/05878; WO97/16426; WO97/16441; and WO97/16442. Substituted aryl andheteroaryl fused pyrrole compounds for use in the treatment of cytokinemediated diseases have been described in WO98/22457. Substitutedpyridine, pyrimidine, pyrimidinone, and pyridazine compounds for use inthe treatment of cytokine mediated diseases have been described inWO98/24780; WO98/24782; WO99/24404; and WO99/32448.

Internalizing Proteins

The TAT protein sequence (from HIV) can be used to internalize proteinsinto a cell by targeting the lipid bi-layer component of the cellmembrane. See e.g., Falwell et al., Proc. Natl. Acad. Sci. USA,91:664-668 (1994). For example, an 11 amino acid sequence (YGRKKRRQRRR;SEQ id NO: X) of the HIV tat protein (termed the “protein transductiondomain”, or TAT PDT) has shown to mediate delivery of large bioactiveproteins such as β-galactosidase and ^(p27)Kip across the cytoplasmicmembrane and the nuclear membrane of a cell. See Schwarze et al.,Science, 285:1569-1572 (1999); and Nagahara et al., Nature Medicine,4:1449-1452 (1998). Schwarze et al., supra, demonstrated that culturedcells acquired β-galactosidase activity when exposed to a fusion of theTAT-PDT and β-galactosidase. Injection of mice with TAT-β-gal fusionproteins resulted in β-gal expression in a number of tissues, includingliver, kidney, lung, heart and brain tissue.

It will thus be appreciated that the TAT protein sequence may be used tointernalize a desired protein or polypeptide into a cell. In the contextof the present invention, the TAT protein sequence can be fused toanother molecule such as a MK61 antagonist (i.e. anti-MK61 selectivebinding agent, small molecule, soluble receptor, or antisenseoligonucleotide) can be administered intracellularly to inhibit theactivity of an MK61 molecule. As used herein, the term “MK61 molecule”refers to both MK61 nucleic acid molecules and MK61 polypeptides asdefined herein. Where desired, the MK61 protein itself or a peptidefragment or modified form of MI61, may be fused to such a proteintransducer for administering to cells using the procedures describedabove.

Cell Source Identification Using MK61 Polypeptides

In accordance with certain embodiments of the invention, it may beuseful to be able to determine the source of a certain cell typeassociated with an MK61 polypeptide. For example, it may be useful todetermine the origin of a disease or pathological condition as an aid inselecting an appropriate therapy.

Therapeutic Uses

The polypeptides and agonists and antagonists of the invention are alsouseful in the diagnosis and treatment of a number of diseases anddisorders, including those recited herein. These include, but are notlimited to diseases and disorders involving leukocyte and/or osteoclastproliferation, differentiation, survival, and/or apoptosis. Thepolypeptides and agonists and antagonists of the invention are alsouseful in regulating growth, survival and/or apoptosis of lymphoma,leukemia, and other cancer cells.

hMK61T1 was identified from a PMA treated cancer cell line. Therefore,production of the hMK61T1 cell-surface receptor may be regulated by PMAand/or other growth signals at the RNA splicing level. A peptidecorresponding to a part of the extracellular domain of hMK61T1 wasidentified in human urine and serum through proteomics analysis.Furthermore, selective expression of hMK61 was observed in spleen, lymphnodes, peripheral blood leukocytes, and fetal liver as determined byNorthern blotting. The polypeptides and agonists and antagonists of theinvention are thus also useful in the diagnosis and/or treatment ofdisorders of the immune system (as is described herein), as well as inthe protection and regeneration of the liver.

Many diseases and medical conditions are associated with TNF and areoften categorized as inflammatory conditions. TNF-associated diseasesinclude, but are not limited to, spontaneous or experimental diseases ormedical conditions if associated with elevated levels of TNF in bodilyfluids or tissue, or if cells or tissues taken from the body produceelevated levels of TNF in culture. In many cases, TNF-associateddiseases may also be recognized by: (1) pathological findings associatedwith the disease or medical condition can be mimicked experimentally inanimals by the administration or upregulation of expression of TNF, or(2) a pathology induced in experimental animal models of the disease ormedical condition can be inhibited or abolished by treatment with agentsthat inhibit the action of TNF. It will be understood, however, that themechanism of action of the MK61 polypeptides is not necessarily theinhibition of TNF.

A non-exclusive list of acute and chronic TNF-associated diseasesincludes, but is not limited to, the following: cachexia/anorexia;cancer (e.g., leukemias); chronic fatigue syndrome; coronary conditionsand indications, including congestive heart failure, coronaryrestenosis, myocardial infarction, and coronary artery bypass graft;depression; diabetes (e.g., juvenile onset Type 1 and diabetesmellitus); endometriosis, endometritis, and related conditions;fibromyalgia or analgesia; graft versus host rejection; hyperalgesia;inflammatory bowel diseases, including Crohn's disease and Clostridiumdifficile-associated diarrhea; ischemic, including cerebral ischemia(brain injury as a result of trauma, epilepsy, hemorrhage or stroke,each of which may lead to neurodegeneration); lung diseases (e.g., adultrespiratory distress syndrome, asthma, and pulmonary fibrosis); multiplesclerosis; neuroinflammatory diseases; ocular diseases and conditions,including corneal transplant, ocular degeneration and uveitis; pain,including cancer-related pain; pancreatitis; periodontal diseases;prostatitis (bacterial or non-bacterial) and related conditions;psoriasis and related conditions; pulmonary fibrosis; reperfusioninjury; rheumatic diseases (e.g., rheumatoid arthritis, osteoarthritis,juvenile (rheumatoid) arthritis, seronegative polyarthritis, ankylosingspondylitis, Reiter's syndrome and reactive arthritis, Still's disease,psoriatic arthritis, enteropathic arthritis, polymyositis,dermatomyositis, scleroderma, systemic sclerosis, vasculitis (e.g.,Kawasaki's disease), cerebral vasculitis, Lyme disease,staphylococcal-induced (“septic”) arthritis, Sjögren's syndrome,rheumatic fever, polychondritis and polymyalgia rheumatica and giantcell arteritis); septic shock; side effects from radiation therapy;systemic lupus erythematosus; temporal mandibular joint disease;thyroiditis; tissue transplantation or an inflammatory conditionresulting from strain, sprain: cartilage damage, trauma, orthopedicsurgery, infection (e.g., HIV, Clostridium difficile and relatedspecies) or other disease process.

TNFα inhibitors may act by downregulating or inhibiting TNF production,binding free TNF, interfering with TNF binding to its receptor, orinterfering with modulation of TNF signaling after binding to itsreceptor. The term “TNFα inhibitor” thus includes solubilized TNFreceptors, antibodies to TNF, antibodies to TNF receptor, inhibitors ofTNFα converting enzyme (TACE), and other molecules that affect TNFactivity.

TNFα inhibitors of various kinds are disclosed in the art, including thefollowing references:

European patent applications 308 378; 422 339; 393 438; 398 327; 412486; 418 014, 417 563, 433 900; 464 533; 512 528; 526 905; 568 928; 663210; 542 795; 818 439; 664 128; 542 795; 741 707; 874 819; 882 714; 880970; 648 783; 731 791; 895 988; 550 376; 882 714; 853 083; 550 376; 943616;

U.S. Pat. Nos. 5,136,021; 5,929,117; 5,948,638; 5,807,862; 5,695,953;5,834,435; 5,817,822; 5,830,742; 5,834,435; 5,851,556; 5,853,977;5,359,037; 5,512,544; 5,695,953; 5,811,261; 5,633,145; 5,863,926;5,866,616; 5,641,673; 5,869,677; 5,869,511; 5,872,146; 5,854,003;5,856,161; 5,877,222; 5,877,200; 5,877,151; 5,886,010; 5,869,660;5,859,207; 5,891,883; 5,877,180; 5,955,480; 5,955,476; 5,955,435;

International (WO) patent applications 90/13575, 91/03553, 92/01002,92/13095, 92/16221, 93/07863, 93/21946, 93/19777, 95/34326, 96/28546,98/27298, 98/30541, 96/38150, 96/38150, 97/18207, 97/15561, 97/12902,96/25861, 96/12735, 96/11209, 98/39326, 98/39316, 98/38859, 98/39315,98/42659, 98/39329, 98/43959, 98/45268, 98/47863, 96/33172, 96/20926,97/37974, 97/37973, 96/35711, 98/51665, 98/43946, 95/04045, 98/56377,97/12244, 99/00364, 99/00363, 98/57936, 99/01449, 99/01139, 98/56788,98/56756, 98/53842, 98/52948, 98/52937, 99/02510, 97/43250, 99/06410,99/06042, 99/09022, 99/08688, 99/07679, 99/09965, 99/07704, 99/06041,99/37818, 99/37625, 97/11668;

Japanese (JP) patent applications 10147531, 10231285, 10259140, and10130149, 10316570, 11001481, and 127,800/1991; German (DE) application19731521; British (GB) applications 2 218 101, 2 326 881, 2 246 569.

For purposes of this invention, the molecules disclosed in thesereferences and the molecules disclosed in the references (see below) arecollectively termed “TNFα inhibitors”.

For example, EP 393,438 and EP 422,339 teach the amino acid and nucleicacid sequences of a soluble TNF receptor type I (also known as sTNFR-Ior 30 kDa TNF inhibitor) and a soluble TNF receptor type II (also knownas sTNFR-II or 40 kDa TNF inhibitor), collectively termed “sTNFRs”, aswell as modified forms thereof (e.g., fragments, functional derivativesand variants). EP 393,438 and EP 422,339 also disclose methods forisolating the genes responsible for coding the inhibitors, cloning thegene in suitable vectors and cell types, and expressing the gene toproduce the inhibitors.

sTNFR-I and sTNFR-II are members of the nerve growth factor/TNF receptorsuperfamily of receptors which includes the nerve growth factor receptor(NGF), the B-cell antigen CD40, 4-1BB, the rat T-cell antigen MRC OX40,the fas antigen, and the CD27 and CD30 antigens (Smith et al., Science,248:1019-1023 (1990)). The most conserved feature among this group ofcell surface receptors is the cysteine-rich extracellular ligand bindingdomain, which can be divided into four repeating motifs of about fortyamino acids and which contains 4-6 cysteine residues at positions whichare well conserved (Smith et al. (1990), supra).

As contemplated by the present invention, an MK61 polypeptide may beadministered as an adjunct to other therapy and also with otherpharmaceutical formulations suitable for the indication being treated. AMK61 polypeptide and any of one or more additional therapies orpharmaceutical formulations may be administered separately,sequentially, or simultaneously.

In a specific embodiment, the present invention is directed to the useof a MK61 polypeptide in combination (pretreatment, post-treatment, orconcurrent treatment) with any of one or more interleukin-1 (IL-1)inhibitors for the treatment of TNF-responsive disease. Classes ofinterleukin-1 inhibitors include interleukin-1 receptor antagonists (anycompound capable of specifically preventing activation of cellularreceptors to IL-1) such as IL-1ra, as described below; anti-IL-1receptor monoclonal antibodies (e.g., EP 623,674); IL-1 binding proteinssuch as soluble IL-1 receptors (e.g., U.S. Pat. Nos. 5,492,888,5,488,032, 5,464,937, 5,319,071 and 5,180,812); anti-IL-1 monoclonalantibodies (e.g., WO95/01997, WO94/02627, WO90/06371, U.S. Pat. No.4,935,343, EP 364,778, EP 267,611 and EP 220,063); IL-1 receptoraccessory proteins (e.g., WO96/23067), and other compounds and proteinswhich block in vivo synthesis or extracellular release of IL-1.

Interleukin-1 receptor antagonist (IL-1ra) is a human protein that actsas a natural inhibitor of interleukin-1. Interleukin-1 receptorantagonists, as well as the methods of making and methods of usingthereof, are described in U.S. Pat. No. 5,075,222; WO91/08285;WO91/17184; AU9173636; WO92/16221; WO93/21946; WO94/06457; WO94/21275;FR2706772; WO94/21235; DE4219626; WO94/20517; WO96/22793 and WO97/28828,the disclosures of which are incorporated herein by reference. Theproteins include glycosylated as well as non-glycosylated IL-1 receptorantagonists.

Specifically, three preferred forms of IL-1ra (IL-1raα, IL-1raβ andIL-1rax), each being encoded by the same DNA coding sequence andvariants thereof, are disclosed and described in U.S. Pat. No.5,075,222. Methods for producing IL-1 inhibitors, particularly IL-1ras,are also disclosed in the 5,075,222 patent.

An additional class of interleukin-1 inhibitors includes compoundscapable of specifically preventing activation of cellular receptors toIL-1. Such compounds include IL-1 binding proteins, such as solublereceptors and monoclonal antibodies. Such compounds also includemonoclonal antibodies to the receptors.

A further class of interleukin-1 inhibitors includes compounds andproteins which block in vivo synthesis and/or extracellular release ofIL-1. Such compounds include agents which affect transcription of IL-1genes or processing of IL-1 preproteins.

In a specific embodiment, the present invention is directed to the useof an MK61 polypeptide in combination (pretreatment, post-treatment orconcurrent treatment) with secreted or soluble human fas antigen orrecombinant versions thereof (WO96/20206 and Mountz et al., J.Immunology, 155:4829-4837; and EP 510,691, the disclosures of which arehereby incorporated by reference). WO96/20206 discloses secreted humanfas antigen (native and recombinant, including an Ig fusion protein),methods for isolating the genes responsible for coding the solublerecombinant human fas antigen, methods for cloning the gene in suitablevectors and cell types, and methods for expressing the gene to producethe inhibitors. EP 510,691 teaches DNAs coding for human fas antigen,including soluble fas antigen, vectors expressing for said DNAs andtransformants transfected with the vector. When administeredparenterally, doses of a secreted or soluble fas antigen fusion proteineach are generally from about 1 micrograms/kg to about 100micrograms/kg.

Present treatment of TNF-responsive diseases, including acute andchronic inflammation such as rheumatic diseases, commonly includes theuse of first line drugs for control of pain and inflammation; thesedrugs are classified as non-steroidal, anti-inflammatory drugs (NSAIDs).Secondary treatments include corticosteroids, slow acting antirheumaticdrugs (SAARDs) or disease modifying (DM) drugs. Information regardingthe following compounds can be found in The Merck Manual of Diagnosisand Therapy, Sixteenth Edition, Merck, Sharp & Dohme ResearchLaboratories, Merck & Co., Rahway, N.J. (1992) and in Pharmaprojects,PJB Publications Ltd.

In a specific embodiment, the present invention is directed to the useof an MK61 polypeptide and any of one or more NSAIDs for the treatmentof TNF-responsive diseases, including acute and chronic inflammationsuch as rheumatic diseases; and graft versus host disease. NSAIDs owetheir anti-inflammatory action, at least in part, to the inhibition ofprostaglandin synthesis (Goodman and Gilman in “The PharmacologicalBasis of Therapeutics,” MacMillan 7th Edition (1985)). NSAIDs can becharacterized into at least nine groups: (1) salicylic acid derivatives;(2) propionic acid derivatives; (3) acetic acid derivatives; (4) fenamicacid derivatives; (5) carboxylic acid derivatives; (6) butyric acidderivatives; (7) oxicams; (8) pyrazoles and (9) pyrazolones.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more salicylic acidderivatives, prodrug esters or pharmaceutically acceptable saltsthereof. Such salicylic acid derivatives, prodrug esters andpharmaceutically acceptable salts thereof comprise: acetaminosalol,aloxiprin, aspirin, benorylate, bromosaligenin, calciumacetylsalicylate, choline magnesium trisalicylate, magnesium salicylate,choline salicylate, diflusinal, etersalate, fendosal, gentisic acid,glycol salicylate, imidazole salicylate, lysine acetylsalicylate,mesalamine, morpholine salicylate, 1-naphthyl salicylate, olsalazine,parsalmide, phenyl acetylsalicylate, phenyl salicylate, salacetamide,salicylamide O-acetic acid, salsalate, sodium salicylate andsulfasalazine. Structurally related salicylic acid derivatives havingsimilar analgesic and anti-inflammatory properties are also intended tobe encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more propionic acidderivatives, prodrug esters or pharmaceutically acceptable saltsthereof. The propionic acid derivatives, prodrug esters andpharmaceutically acceptable salts thereof comprise: alminoprofen,benoxaprofen, bucloxic acid, carprofen, dexindoprofen, fenoprofen,flunoxaprofen, fluprofen, flurbiprofen, furcloprofen, ibuprofen,ibuprofen aluminum, ibuproxam, indoprofen, isoprofen, ketoprofen,loxoprofen, miroprofen, naproxen, naproxen sodium, oxaprozin,piketoprofen, pimeprofen, pirprofen, pranoprofen, protizinic acid,pyridoxiprofen, suprofen, tiaprofenic acid and tioxaprofen. Structurallyrelated propionic acid derivatives having similar analgesic andanti-inflammatory properties are also intended to be encompassed by thisgroup.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more acetic acidderivatives, prodrug esters or pharmaceutically acceptable saltsthereof. The acetic acid derivatives, prodrug esters andpharmaceutically acceptable salts thereof comprise: acemetacin,alclofenac, amfenac, bufexamac, cinmetacin, clopirac, delmetacin,diclofenac potassium, diclofenac sodium, etodolac, felbinac,fenclofenac, fenclorac, fenclozic acid, fentiazac, furofenac,glucametacin, ibufenac, indomethacin, isofezolac, isoxepac, lonazolac,metiazinic acid, oxametacin, oxpinac, pimetacin, proglumetacin,sulindac, talmetacin, tiaramide, tiopinac, tolmetin, tolmetin sodium,zidometacin and zomepirac. Structurally related acetic acid derivativeshaving similar analgesic and anti-inflammatory properties are alsointended to be encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more fenamic acidderivatives, prodrug esters or pharmaceutically acceptable saltsthereof. The fenamic acid derivatives, prodrug esters andpharmaceutically acceptable salts thereof comprise: enfenamic acid,etofenamate, flufenamic acid, isonixin, meclofenamic acid, meclofenamatesodium, medofenamic acid, mefenamic acid, niflumic acid, talniflumate,terofenamate, tolfenamic acid and ufenamate. Structurally relatedfenamic acid derivatives having similar analgesic and anti-inflammatoryproperties are also intended to be encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more carboxylic acidderivatives, prodrug esters or pharmaceutically acceptable saltsthereof. The carboxylic acid derivatives, prodrug esters andpharmaceutically acceptable salts thereof which can be used comprise:clidanac, diflunisal, flufenisal, inoridine, ketorolac and tinoridine.Structurally related carboxylic acid derivatives having similaranalgesic and anti-inflammatory properties are also intended to beencompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more butyric acidderivatives, prodrug esters or pharmaceutically acceptable saltsthereof. The butyric acid derivatives, prodrug esters andpharmaceutically acceptable salts thereof comprise: bumadizon,butibufen, fenbufen and xenbucin. Structurally related butyric acidderivatives having similar analgesic and anti-inflammatory propertiesare also intended to be encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more oxicams, prodrug estersor pharmaceutically acceptable salts thereof. The oxicams, prodrugesters and pharmaceutically acceptable salts thereof comprise: droxicam,enolicam, isoxicam, piroxicam, sudoxicam, tenoxicam and4-hydroxyl-1,2-benzothiazine 1,1-dioxide 4-(N-phenyl)-carboxamide.Structurally related oxicams having similar analgesic andanti-inflammatory properties are also intended to be encompassed by thisgroup.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatment,or concurrent treatment) with any of one or more pyrazoles, prodrugesters or pharmaceutically acceptable salts thereof. The pyrazoles,prodrug esters and pharmaceutically acceptable salts thereof which maybe used comprise: difenamizole and epirizole. Structurally relatedpyrazoles having similar analgesic and anti-inflammatory properties arealso intended to be encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more pyrazolones, prodrugesters or pharmaceutically acceptable salts thereof. The pyrazolones,prodrug esters and pharmaceutically acceptable salts thereof which maybe used comprise: apazone, azapropazone, benzpiperylon, feprazone,mofebutazone, morazone, oxyphenbutazone, phenylbutazone, pipebuzone,propylphenazone, ramifenazone, suxibuzone and thiazolinobutazone.Structurally related pyrazalones having similar analgesic andanti-inflammatory properties are also intended to be encompassed by thisgroup.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more of the followingNSAIDs: ε-acetamidocaproic acid, S-adenosylmethionine,3-amino-4-hydroxybutyric acid, amixetrine, anitrazafen, antrafenine,bendazac, bendazac lysinate, benzydamine, beprozin, broperamole,bucolome, bufezolac, ciproquazone, cloximate, dazidamine, deboxamet,detomidine, difenpiramide, difenpyramide, difisalamine, ditazol,emorfazone, fanetizole mesylate, fenflumizole, floctafenine, flumizole,flunixin, fluproquazone, fopirtoline, fosfosal, guaimesal, guaiazolene,isonixirn, lefetamine HCl, leflunomide, lofemizole, lotifazole, lysinclonixinate, meseclazone, nabumetone, nictindole, nimesulide, orgotein,orpanoxin, oxaceprol, oxapadol, paranyline, perisoxal, perisoxalcitrate, pifoxime, piproxen, pirazolac, pirfenidone, proquazone,proxazole, thielavin B, tiflamizole, timegadine, tolectin, tolpadol,tryptamid and those designated by company code number such as 480156S,AA861, AD1590, AFP802, AFP860, AI77B, AP504, AU8001, BPPC, BW540C,CHINOIN 127, CN100, EB382, EL508, F1044, FK-506, GV3658, ITF182,KCNTEI6090, KME4, LA2851, MR714, MR897, MY309, ON03144, PR823, PV102,PV108, R830, RS2131, SCR152, SH440, SIR133, SPAS510, SQ27239, ST281,SY6001, TA60, TAI-901 (4-benzoyl-1-indancarboxylic acid), TVX2706,U60257, UR2301 and WY41770. Structurally related NSAIDs having similaranalgesic and anti-inflammatory properties to the NSAIDs are alsointended to be encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more corticosteroids,prodrug esters or pharmaceutically acceptable salts thereof for thetreatment of TNF-responsive diseases, including acute and chronicinflammation such as rheumatic diseases, graft versus host disease andmultiple sclerosis. Corticosteroids, prodrug esters and pharmaceuticallyacceptable salts thereof include hydrocortisone and compounds which arederived from hydrocortisone, such as 21-acetoxypregnenolone,alclomerasone, algestone, amcinonide, beclomethasone, betamethasone,betamethasone valerate, budesonide, chloroprednisone, clobetasol,clobetasol propionate, clobetasone, clobetasone butyrate, clocortolone,cloprednol, corticosterone, cortisone, cortivazol, deflazacon, desonide,desoximerasone, dexamethasone, diflorasone, diflucortolone,difluprednate, enoxolone, fluazacort, flucloronide, flumethasone,flumethasone pivalate, flucinolone acetonide, flunisolide, fluocinonide,fluorocinolone acetonide, fluocortin butyl, fluocortolone, fluocortolonehexanoate, diflucortolone valerate, fluorometholone, fluperoloneacetate, fluprednidene acetate, fluprednisolone, flurandenolide,formocortal, halcinonide, halometasone, halopredone acetate,hydrocortamate, hydrocortisone, hydrocortisone acetate, hydrocortisonebutyrate, hydrocortisone phosphate, hydrocortisone 21-sodium succinate,hydrocortisone tebutate, mazipredone, medrysone, meprednisone,methylprednisolone, mometasone furoate, paramethasone, prednicarbate,prednisolone, prednisolone 21-diedryaminoacetate, prednisolone sodiumphosphate, prednisolone sodium succinate, prednisolone sodium21-m-sulfobenzoate, prednisolone sodium 21-stearoglycolate, prednisolonetebutate, prednisolone 21-trimethylacetate, prednisone, prednival,prednylidene, prednylidene 21-diethylaminoacetate, tixocortol,triamcinolone, triamcinolone acetonide, triamcinolone benetonide andtriamcinolone hexacetonide. Structurally related corticosteroids havingsimilar analgesic and anti-inflammatory properties are also intended tobe encompassed by this group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more slow-actingantirheumatic drugs (SAARDs) or disease modifying antirheumatic drugs(DMARDS), prodrug esters or pharmaceutically acceptable salts thereoffor the treatment of TNF-responsive diseases, including acute andchronic inflammation such as rheumatic diseases, graft versus hostdisease and multiple sclerosis. SAARDs or DMARDS, prodrug esters andpharmaceutically acceptable salts thereof comprise: allocupreide sodium,auranofin, aurothioglucose, aurothioglycanide, azathioprine, brequinarsodium, bucillamine, calcium 3-aurothio-2-propanol-1-sulfonate,chlorambucil, chloroquine, clobuzarit, cuproxoline, cyclophosphamide,cyclosporin, dapsone, 15-deoxyspergualin, diacerein, glucosamine, goldsalts (e.g., cycloquine gold salt, gold sodium thiomalate, gold sodiumthiosulfate), hydroxychloroquine, hydrbxychloroquine sulfate,hydroxyurea, kebuzone, levamisole, lobenzarit, melittin,6-mercaptopurine, methotrexate, mizoribine, mycophenolate mofetil,myoral, nitrogen mustard, D-penicillamine, pyridinol imidazoles such asSKNF86002 and SB203580, rapamycin, thiols, thymopoietin and vincristine.Structurally related SAARDs or DMARDs having similar analgesic andanti-inflammatory properties are also intended to be encompassed by thisgroup.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more COX2 inhibitors,prodrug esters or pharmaceutically acceptable salts thereof for thetreatment of TNF-responsive diseases, including acute and chronicinflammation. Examples of COX2 inhibitors, prodrug esters orpharmaceutically acceptable salts thereof include, for example,celecoxib. Structurally related COX2 inhibitors having similar analgesicand anti-inflammatory properties are also intended to be encompassed bythis group.

In a more specific embodiment, the present invention is directed to theuse of a MK61 polypeptide in combination (pretreatment, post-treatmentor concurrent treatment) with any of one or more antimicrobials, prodrugesters or pharmaceutically acceptable salts thereof for the treatment ofTNF-responsive diseases, including acute and chronic inflammation.Antimicrobials include, for example, the broad classes of penicillins,cephalosporins and other beta-lactams, aminoglycosides, azoles,quinolones, macrolides, rifamycins, tetracyclines, sulfonamides,lincosamides and polymyxins. The penicillins include, but are notlimited to penicillin G, penicillin V, methicillin, nafcillin,oxacillin, cloxacillin, dicloxacillin, floxacillin, ampicillin,ampicillin/sulbactam, amoxicillin, amoxicillin/clavulanate, hetacillin,cyclacillin, bacampicillin, carbenicillin, carbenicillin indanyl,ticarcillin, ticarcillin/clavulanate, azlocillin, mezlocillin,peperacillin, and mecillinam. The cephalosporins and other beta-lactamsinclude, but are not limited to cephalothin, cephapirin, cephalexin,cephradine, cefazolin, cefadroxil, cefaclor, cefamandole, cefotetan,cefoxitin, ceruroxime, cefonicid, ceforadine, cefixime, cefotaxime,moxalactam, ceftizoxime, cetriaxone, cephoperazone, ceftazidime,imipenem and aztreonam. The aminoglycosides include, but are not limitedto streptomycin, gentamicin, tobramycin, amikacin, netilmicin, kanamycinand neomycin. The azoles include, but are not limited to fluconazole.The quinolones include, but are not limited to nalidixic acid,norfloxacin, enoxacin, ciprofloxacin, ofloxacin, sparfloxacin andtemafloxacin. The macrolides include, but are not limited toerythomycin, spiramycin and azithromycin. The rifamycins include, butare not limited to rifampin. The tetracyclines include, but are notlimited to spicycline, chlortetracycline, clomocycline, demeclocycline,deoxycycline, guamecycline, lymecycline, meclocycline, methacycline,minocycline, oxytetracycline, penimepicycline, pipacycline,rolitetracycline, sancycline, senociclin and tetracycline. Thesulfonamides include, but are not limited to sulfanilamide,sulfamethoxazole, sulfacetamide, sulfadiazine, sulfisoxazole andco-trimoxazole (trimethoprim/sulfamethoxazole). The lincosamidesinclude, but are not limited to clindamycin and lincomycin. Thepolymyxins (polypeptides) include, but are not limited to polymyxin Band colistin.

MK61 Compositions and Administration

Therapeutic compositions within the scope of the present inventioninclude MK61 pharmaceutical compositions that may comprise atherapeutically effective amount of an MK61 polypeptide or an MK61nucleic acid molecule in admixture with a pharmaceutically orphysiologically acceptable formulation agent selected for suitabilitywith the mode of administration to a human or non-human animal such as amammal. Pharmaceutical compositions may comprise a therapeuticallyeffective amount of one or more MK61 selective binding agents inadmixture with a pharmaceutically or physiologically acceptableformulation agent selected for suitability with the mode ofadministration.

Acceptable formulation materials preferably are nontoxic to recipientsat the dosages and concentrations employed.

The pharmaceutical composition may contain formulation materials formodifying, maintaining or preserving, for example, the pH, osmolarity,viscosity, clarity, color, isotonicity, odor, sterility, stability, rateof dissolution or release, adsorption or penetration of the composition.Suitable formulation materials include, but are not limited to, aminoacids (such as glycine, glutamine, asparagine, arginine or lysine);antimicrobials; antioxidants (such as ascorbic acid, sodium sulfite orsodium hydrogen-sulfite); buffers (such as borate, bicarbonate,Tris-HCl, citrates, phosphates or other organic acids); bulking agents(such as mannitol or glycine); chelating agents (such as ethylenediaminetetraacetic acid (EDTA)); complexing agents (such as caffeine,polyvinylpyrrolidone, beta-cyclodextrin orhydroxypropyl-beta-cyclodextrin); fillers; monosaccharides;disaccharides; and other carbohydrates (such as glucose, mannose ordextrins); proteins (such as serum albumin, gelatin or immunoglobulins);coloring, flavoring and diluting agents; emulsifying agents; hydrophilicpolymers (such as polyvinylpyrrolidone); low molecular weightpolypeptides; salt-forming counterions (such as sodium); preservatives(such as benzalkonium chloride, benzoic acid, salicylic acid,thimerosal, phenethyl alcohol, methylparaben, propylparaben,chlorhexidine, sorbic acid or hydrogen peroxide); solvents (such asglycerin, propylene glycol or polyethylene glycol); sugar alcohols (suchas mannitol or sorbitol); suspending agents; surfactants or wettingagents (such as pluronics, PEG, sorbitan esters, polysorbates such aspolysorbate 20, polysorbate 80, triton, tromethamine, lecithin,cholesterol, tyloxapal); stability enhancing agents (such as sucrose orsorbitol); tonicity enhancing agents (such as alkali metal halides,preferably sodium or potassium chloride, mannitol sorbitol); deliveryvehicles; diluents; excipients and/or pharmaceutical adjuvants.(Remington's Pharmaceutical Sciences, 18^(th) Edition, A. R. Gennaro,ed., Mack Publishing Company (1990).

The optimal pharmaceutical composition will be determined by one skilledin the art depending upon, for example, the intended route ofadministration, delivery format and desired dosage. See, for example,Remington's Pharmaceutical Sciences, supra. Such compositions mayinfluence the physical state, stability, rate of in vivo release andrate of in vivo clearance of the MK61 molecule.

The primary vehicle or carrier in a pharmaceutical composition may beeither aqueous or non-aqueous in nature. For example, a suitable vehicleor carrier may be water for injection, physiological saline solution orartificial cerebrospinal fluid, possibly supplemented with othermaterials common in compositions for parenteral administration. Neutralbuffered saline or saline mixed with serum albumin are further exemplaryvehicles. Other exemplary pharmaceutical compositions comprise Trisbuffer of about pH 7.0-8.5, or acetate buffer of about pH 4.0-5.5, whichmay further include sorbitol or a suitable substitute therefor. In oneembodiment of the present invention, MK61 polypeptide compositions maybe prepared for storage by mixing the selected composition having thedesired degree of purity with optional formulation agents (Remington'sPharmaceutical Sciences, supra) in the form of a lyophilized cake or anaqueous solution. Further, the MK61 polypeptide product may beformulated as a lyophilizate using appropriate excipients such assucrose.

The MK61 pharmaceutical compositions can be selected for parenteraldelivery. Alternatively, the compositions may be selected for inhalationor for delivery through the digestive tract, such as orally, or throughother delivery routes known in the art. The preparation of suchpharmaceutically acceptable compositions is within the skill of the art.

The formulation components are present in concentrations that areacceptable to the site of administration. For example, buffers are usedto maintain the composition at physiological pH or at a slightly lowerpH, typically within a pH range of from about 5 to about 8.

When parenteral administration is contemplated, the therapeuticcompositions for use in this invention may be in the form of apyrogen-free, parenterally acceptable aqueous solution comprising thedesired MK61 molecule in a pharmaceutically acceptable vehicle. Aparticularly suitable vehicle for parenteral injection is steriledistilled water in which an MK61 molecule is formulated as a sterile,isotonic solution, properly preserved. Yet another preparation caninvolve the formulation of the desired molecule with an agent, such asinjectable microspheres, bio-erodible particles, polymeric compounds(such as polylactic acid or polyglycolic acid), beads or liposomes, thatprovides for the controlled or sustained release of the product whichmay then be delivered via a depot injection. Hyaluronic acid may also beused, and this may have the effect of promoting sustained duration inthe circulation. Other suitable means for the introduction of thedesired molecule include implantable drug delivery devices.

In one embodiment, a pharmaceutical composition may be formulated forinhalation. For example, an MK61 molecule may be formulated as a drypowder for inhalation. MK61 polypeptide or MK61 nucleic acid moleculeinhalation solutions may also be formulated with a propellant foraerosol delivery. In yet another embodiment, solutions may be nebulized.Pulmonary administration is further described in PCT application no.PCT/US94/001875, which describes pulmonary delivery of chemicallymodified proteins.

It is also contemplated that certain formulations may be administeredorally. In one embodiment of the present invention, MK61 molecules whichare administered in this fashion can be formulated with or without thosecarriers customarily used in the compounding of solid dosage forms suchas tablets and capsules. For example, a capsule may be designed torelease the active portion of the formulation at the point in thegastrointestinal tract when bioavailability is maximized andpre-systemic degradation is minimized. Additional agents can be includedto facilitate absorption of the MK61 molecule. Diluents, flavorings, lowmelting point waxes, vegetable oils, lubricants, suspending agents,tablet disintegrating agents, and binders may also be employed.

Another pharmaceutical composition may involve an effective quantity ofMK61 molecules in a mixture with non-toxic excipients which are suitablefor the manufacture of tablets. By dissolving the tablets in sterilewater, or another appropriate vehicle, solutions can be prepared inunit-dose form. Suitable excipients include, but are not limited to,inert diluents, such as calcium carbonate, sodium carbonate orbicarbonate, lactose, or calcium phosphate; or binding agents, such asstarch, gelatin, or acacia; or lubricating agents such as magnesiumstearate, stearic acid, or talc.

Additional MK61 pharmaceutical compositions will be evident to thoseskilled in the art, including formulations involving MK61 polypeptidesin sustained- or controlled-delivery formulations. Techniques forformulating a variety of other sustained- or controlled-delivery means,such as liposome carriers, bio-erodible microparticles or porous beadsand depot injections, are also known to those skilled in the art. Seefor example, PCT Application No. PCT/US93/00829 which describes thecontrolled release of porous polymeric microparticles for the deliveryof pharmaceutical compositions. Additional examples of sustained-releasepreparations include semipermeable polymer matrices in the form ofshaped articles, e.g. films, or microcapsules. Sustained releasematrices may include polyesters, hydrogels, polylactides (U.S. Pat. No.3,773,919 and EP 058,481), copolymers of L-glutamic acid and gammaethyl-L-glutamate (Sidman et al., Biopolymers, 22:547-556 (1983)), poly(2-hydroxyethyl-methacrylate) (Langer et al., J. Biomed. Mater. Res.,15:167-277 (1981) and Langer, Chem. Tech., 12:98-105 (1982)), ethylenevinyl acetate (Langer et al., supra) or poly-D(−)-3-hydroxybutyric acid(EP 133,988). Sustained release compositions may also include liposomes,which can be prepared by any of several methods known in the art. Seee.g., Eppstein et al., Proc. Natl. Acad. Sci. USA, 82:3688-3692 (1985);EP 036,676; EP 088,046 and EP 143,949.

The MK61 pharmaceutical composition to be used for in vivoadministration typically must be sterile. This may be accomplished byfiltration through sterile filtration membranes. Where the compositionis lyophilized, sterilization using this method may be conducted eitherprior to or following lyophilization and reconstitution. The compositionfor parenteral administration may be stored in lyophilized form or in asolution. In addition, parenteral compositions generally are placed intoa container having a sterile access port, for example, an intravenoussolution bag or vial having a stopper pierceable by a hypodermicinjection needle.

Once the pharmaceutical composition has been formulated, it may bestored in sterile vials as a solution, suspension, gel, emulsion, solid,or as a dehydrated or lyophilized powder. Such formulations may bestored either in a ready-to-use form or in a form (e.g., lyophilized)requiring reconstitution prior to administration.

In a specific embodiment, the present invention is directed to kits forproducing a single-dose administration unit. The kits may each containboth a first container having a dried protein and a second containerhaving an aqueous formulation. Also included within the scope of thisinvention are kits containing single and multi-chambered pre-filledsyringes (e.g., liquid syringes and lyosyringes).

The effective amount of an MK61 pharmaceutical composition to beemployed therapeutically will depend, for example, upon the therapeuticcontext and objectives. One skilled in the art will appreciate that theappropriate dosage levels for treatment will thus vary depending, inpart, upon the molecule delivered, the indication for which the MK61molecule is being used, the route of administration, and the size (bodyweight, body surface or organ size) and condition (the age and generalhealth) of the patient. Accordingly, the clinician may titer the dosageand modify the route of administration to obtain the optimal therapeuticeffect. A typical dosage may range from about 0.1 μg/kg to up to about100 mg/kg or more, depending on the factors mentioned above. In otherembodiments, the dosage may range from 0.1 μg/kg up to about 100 mg/kg;or 1 μg/kg up to about 100 mg/kg; or 5 μg/kg up to about 100 mg/kg.

The frequency of dosing will depend upon the pharmacokinetic parametersof the MK61 molecule in the formulation used. Typically, a clinicianwill administer the composition until a dosage is reached that achievesthe desired effect. The composition may therefore be administered as asingle dose, or as two or more doses (which may or may not contain thesame amount of the desired molecule) over time, or as a continuousinfusion via an implantation device or catheter. Further refinement ofthe appropriate dosage is routinely made by those of ordinary skill inthe art and is within the ambit of tasks routinely performed by them.Appropriate dosages may be ascertained through use of appropriatedose-response data which is routinely obtained.

The route of administration of the pharmaceutical composition is inaccord with known methods, e.g. orally, through injection byintravenous, intraperitoneal, intracerebral (intra-parenchymal),intracerebroventricular, intramuscular, intra-ocular, intraarterial,intraportal, or intralesional routes; by sustained release systems or byimplantation devices. Where desired, the compositions may beadministered by bolus injection or continuously by infusion, or byimplantation device.

Alternatively or additionally, the composition may be administeredlocally via implantation of a membrane, sponge or another appropriatematerial onto which the desired molecule has been absorbed orencapsulated. Where an implantation device is used, the device may beimplanted into any suitable tissue or organ, and delivery of the desiredmolecule may be via diffusion, timed-release bolus, or continuousadministration.

In some cases, it may be desirable to use MK61 pharmaceuticalcompositions in an ex vivo manner. In such instances, cells, tissues ororgans that have been removed from the patient are exposed to MK61pharmaceutical compositions after which the cells, tissues and/or organsare subsequently implanted back into the patient.

In other cases, an MK61 polypeptide can be delivered by implantingcertain cells that have been genetically engineered, using methods suchas those described herein, to express and secrete the polypeptide. Suchcells may be animal or human cells, and may be autologous, heterologous,or xenogeneic. optionally, the cells may be immortalized. In order todecrease the chance of an immunological response, the cells may beencapsulated to avoid infiltration of surrounding tissues. Theencapsulation materials are typically biocompatible, semi-permeablepolymeric enclosures or membranes that allow the release of the proteinproduct(s) but prevent the destruction of the cells by the patient'simmune system or by other detrimental factors from the surroundingtissues.

Additional embodiments of the present invention relate to cells andmethods (e.g., homologous recombination and/or other recombinantproduction methods) for both the in vitro production of therapeuticpolypeptides and for the production and delivery of therapeuticpolypeptides by gene therapy or cell therapy. Homologous and otherrecombination methods may be used to modify a cell that contains anormally transcriptionally-silent MK61 gene, or an underexpressed gene,and thereby produce a cell which expresses therapeutically efficaciousamounts of MK61 polypeptides.

Homologous recombination is a technique originally developed fortargeting genes to induce or correct mutations in transcriptionallyactive genes (Kucherlapati, Prog. in Nucl. Acid Res. & Mol. Biol.,36:301, (1989)). The basic technique was developed as a method forintroducing specific mutations into specific regions of the mammaliangenome (Thomas et al., Cell, 44:419-428 (1986); Thomas and Capecchi,Cell, 51:503-512 (1987); Doetschman et al., Proc. Natl. Acad. Sci.,85:8583-8587 (1988)) or to correct specific mutations within defectivegenes (Doetschman et al., Nature, 330:576-578 (1987)). Exemplaryhomologous recombination techniques are described in U.S. Pat. No.5,272,071 (EP 9193051, EP Publication No. 505500 and PCT/US90/07642,International Publication No. WO 91/09955).

Through homologous recombination, the DNA sequence to be inserted intothe genome can be directed to a specific region of the gene of interestby attaching it to targeting DNA. The targeting DNA is a nucleotidesequence that is complementary (homologous) to a region of the genomicDNA. Small pieces of targeting DNA that are complementary to a specificregion of the genome are put in contact with the parental strand duringthe DNA replication process. It is a general property of DNA that hasbeen inserted into a cell to hybridize and therefore, recombine withother pieces of endogenous DNA through shared homologous regions. Ifthis complementary strand is attached to an oligonucleotide thatcontains a mutation or a different sequence or an additional nucleotide,it too is incorporated into the newly synthesized strand as a result ofthe recombination. As a result of the proofreading function, it ispossible for the new sequence of DNA to serve as the template. Thus, thetransferred DNA is incorporated into the genome.

Attached to these pieces of targeting DNA are regions of DNA which mayinteract with or control the expression of an MK61 polypeptide, e.g.,flanking sequences. For example, a promoter/enhancer element, asuppressor or an exogenous transcription modulatory element is insertedin the genome of the intended host cell in proximity and orientationsufficient to influence the transcription of DNA encoding the desiredMK61 polypeptide. The control element controls a portion of the DNApresent in the host cell genome. Thus, the expression of the desiredMK61 polypeptide may be achieved not by transfection of DNA that encodesthe MK61 gene itself, but rather by the use of targeting DNA (containingregions of homology with the endogenous gene of interest), coupled withDNA regulatory segments that provide the endogenous gene sequence withrecognizable signals for transcription of an MK61 gene.

In an exemplary method, the expression of a desired targeted gene in acell (i.e., a desired endogenous cellular gene) is altered viahomologous recombination into the cellular genome at a preselected siteby the introduction of DNA which includes at least a regulatorysequence, an exon and a splice donor site. These components areintroduced into the chromosomal (genomic) DNA in such a manner thatthis, in effect, results in the production of a new transcription unit(in which the regulatory sequence, the exon and the splice donor sitepresent in the DNA construct are operatively linked to the endogenousgene). As a result of the introduction of these components into thechromosomal DNA, the expression of the desired endogenous gene isaltered.

Altered gene expression, as described herein, encompasses activating (orcausing to be expressed) a gene which is normally silent (unexpressed)in the cell as obtained, as well as increasing the expression of a genewhich is not expressed at physiologically significant levels in the cellas obtained. The embodiments further encompass changing the pattern ofregulation or induction such that it is different from the pattern ofregulation or induction that occurs in the cell as obtained, andreducing (including eliminating) the expression of a gene which isexpressed in the cell as obtained.

One method by which homologous recombination can be used to increase, orcause, MK61 polypeptide production from a cell's endogenous MK61 geneinvolves first using homologous recombination to place a recombinationsequence from a site-specific recombination system (e.g., Cre/loxP,FLP/FRT) (see, Sauer, Current Opinion In Biotechnology, 5:521-527 (1994)and Sauer, Methods In Enzymology, 225:890-900 (1993)) upstream (that is,5′ to) of the cell's endogenous genomic MK61 polypeptide coding region.A plasmid containing a recombination site homologous to the site thatwas placed just upstream of the genomic MK61 polypeptide coding regionis introduced into the modified cell line along with the appropriaterecombinase enzyme. This recombinase enzyme causes the plasmid tointegrate, via the plasmid's recombination site, into the recombinationsite located just upstream of the genomic MK61 polypeptide coding regionin the cell line (Baubonis and Sauer, Nucleic Acids Res., 21:2025-2029,1993 and O'Gorman et al., Science, 251:1351-1355 (1991)). Any flankingsequences known to increase transcription (e.g., enhancer/promoter,intron or translational enhancer), if properly positioned in thisplasmid, would integrate in such a manner as to create a new or modifiedtranscriptional unit resulting in de novo or increased MK61 polypeptideproduction from the cell's endogenous MK61 gene.

A further method to use the cell line in which the site-specificrecombination sequence has been placed just upstream of the cell'sendogenous genomic MK61 polypeptide coding region is to use homologousrecombination to introduce a second recombination site elsewhere in thecell line's genome. The appropriate recombinase enzyme is thenintroduced into the two-recombination-site cell line, causing arecombination event (deletion, inversion, or translocation) (Sauer,Current Opinion In Biotechnology, supra (1994) and Sauer, Methods InEnzymology, supra, (1993)) that would create a new or modifiedtranscriptional unit resulting in de novo or increased MK61 polypeptideproduction from the cell's endogenous MK61 gene.

An additional approach for increasing, or causing, the expression ofMK61 polypeptide from a cell's endogenous MK61 gene involves increasing,or causing, the expression of a gene or genes (e.g., transcriptionfactors) and/or decreasing the expression of a gene or genes (e.g.,transcriptional repressors) in a manner which results in de novo orincreased MK61 polypeptide production from the cell's endogenous MK61gene. This method includes the introduction of a non-naturally occurringpolypeptide (e.g., a polypeptide comprising a site-specific DNA bindingdomain fused to a transcriptional factor domain) into the cell such thatde novo or increased MK61 polypeptide production from the cell'sendogenous MK61 gene results.

The present invention further relates to DNA constructs useful in themethod of altering expression of a target gene. In certain embodiments,the exemplary DNA constructs comprise: (a) one or more targetingsequences; (b) a regulatory sequence; (c) an exon and (d) an unpairedsplice-donor site. The targeting sequence in the DNA construct directsthe integration of elements (a)-(d).into a target gene in a cell suchthat the elements (b)-(d) are operatively linked to sequences of theendogenous target gene. In another embodiment, the DNA constructscomprise: (a) one or more targeting sequences, (b) a regulatorysequence, (c) an exon, (d) a splice-donor site, (e) an intron and (f) asplice-acceptor site, wherein the targeting sequence directs theintegration of elements (a)-(f) such that the elements of (b)-(f) areoperatively linked to the endogenous gene. The targeting sequence ishomologous to the preselected site in the cellular chromosomal DNA withwhich homologous recombination is to occur. In the construct, the exonis generally 3′ of the regulatory sequence and the splice-donor site is3′ of the exon.

If the sequence of a particular gene is known, such as the nucleic acidsequence of MK61 polypeptide presented herein, a piece of DNA that iscomplementary to a selected region of the gene can be synthesized orotherwise obtained, such as by appropriate restriction of the native DNAat specific recognition sites bounding the region of interest. Thispiece serves as a targeting sequence(s) upon insertion into the cell inthat it will hybridize to its homologous region within the genome. It isconventionally believed that if this hybridization occurs during DNAreplication, this piece of DNA, and any additional sequence attachedthereto, will act as an Okazaki fragment and will be incorporated intothe newly synthesized daughter strand of DNA. The present invention,therefore, includes nucleotides encoding a MK61 polypeptide, whichnucleotides may be used as targeting sequences.

MK61 polypeptide cell therapy, e.g., the implantation of cells producingMK61 polypeptides, is also contemplated. This embodiment involvesimplanting cells capable of synthesizing and secreting a biologicallyactive form of MK61 polypeptide. Such MK61 polypeptide-producing cellscan be cells that are natural producers of MK61 polypeptides or may berecombinant cells whose ability to produce MK61 polypeptides has beenaugmented by transformation with a gene encoding the desired MK61polypeptide or with a gene augmenting the expression of MK61polypeptide. Such a modification may be accomplished by means of avector suitable for delivering the gene as well as promoting itsexpression and secretion. In order to minimize a potential immunologicalreaction in patients being administered an MK61 polypeptide, as mayoccur with the administration of a polypeptide of a foreign species, itis preferred that the natural cells producing MK61 polypeptide be ofhuman origin and produce human MK61 polypeptide. Likewise, it ispreferred that the recombinant cells producing MK61 polypeptide betransformed with an expression vector containing a gene encoding a humanMK61 polypeptide.

Implanted cells may be encapsulated to avoid the infiltration ofsurrounding tissue. Human or non-human animal cells may be implanted inpatients in biocompatible, semipermeable polymeric enclosures or inmembranes that allow the release of MK61 polypeptide but prevent thedestruction of the cells by the patient's immune system or by otherdetrimental factors from the surrounding tissue. Alternatively, thepatient's own cells, transformed to produce MK61 polypeptides ex vivo,may be implanted directly into the patient without such encapsulation.

Techniques for the encapsulation of living cells are known in the art,and the preparation of the encapsulated cells and their implantation inpatients may be routinely accomplished. For example, Baetge et al. (WO95/05452 and PCT/US94/C9299) describe membrane capsules containinggenetically engineered cells for the effective delivery of biologicallyactive molecules. The capsules are biocompatible and are easilyretrievable. The capsules encapsulate cells transfected with recombinantDNA molecules comprising DNA sequences coding for biologically activemolecules operatively linked to promoters that are not subject todown-regulation in vivo upon implantation into a mammalian host. Thedevices provide for delivery of the molecules from living cells tospecific sites within a recipient. In addition, see U.S. Pat. Nos.4,892,538, 5,011,472 and 5,106,627. A system for encapsulating livingcells is described in PCT Application no. PCT/US91/00157 of Aebischer etal. See also, PCT Application no. PCT/US91/00155 of Aebischer et al.;Winn et al., Exper. Neurol., 113:322-329 (1991), Aebischer et al.,Exper. Neurol., 111:269-275 (1991); and Tresco et al., ASAIO, 38:17-23(1992).

In vivo and in vitro gene therapy delivery of MK61 polypeptides is alsoenvisioned. One example of a gene therapy technique is to use the MK61gene (either genomic DNA, cDNA and/or synthetic DNA) encoding an MK61polypeptide which may be operably linked to a constitutive or induciblepromoter to form a “gene therapy DNA construct”. The promoter may behomologous or heterologous to the endogenous MK61 gene, provided that itis active in the cell or tissue type into which the construct will beinserted. Other components of the gene therapy DNA construct mayoptionally include, DNA molecules designed for site-specific integration(e.g., endogenous sequences useful for homologous recombination);tissue-specific promoter, enhancer(s) or silencer(s); DNA moleculescapable of providing a selective advantage over the parent cell; DNAmolecules useful as labels to identify transformed cells; negativeselection systems; cell-specific binding agents (as, for example, forcell targeting); cell-specific internalization factors; andtranscription factors to enhance expression by a vector, as well asfactors to enable vector manufacture.

A gene therapy DNA construct can then be introduced into cells (eitherex vivo or in vivo) using viral or non-viral vectors. One means forintroducing the gene therapy DNA construct is by means of viral vectorsas described herein. Certain vectors, such as retroviral vectors, willdeliver the DNA construct to the chromosomal DNA of the cells, and thegene can integrate into the chromosomal DNA. Other vectors will functionas episomes, and the gene therapy DNA construct will remainunintegrated.

In yet other embodiments, regulatory elements can be included for thecontrolled expression of the MK61 gene in the target cell. Such elementsare turned on in response to an appropriate effector. In this way, atherapeutic polypeptide can be expressed when desired. One conventionalcontrol means involves the use of small molecule dimerizers or rapalogs(as described in WO9641865 (PCT/US96/099486); WO9731898 (PCT/US97/03137)and WO9731899 (PCT/US95/03157)) used to dimerize chimeric proteins whichcontain a small molecule-binding domain and a domain capable ofinitiating biological process, such as a DNA-binding protein or atranscriptional activation protein. The dimerization of the proteins canbe used to initiate transcription of the transgene.

An alternative regulation technology uses a method of storing proteinsexpressed from the gene of interest inside the cell as an aggregate orcluster. The gene of interest is expressed as a fusion protein thatincludes a conditional aggregation domain which results in the retentionof the aggregated protein in the endoplasmic reticulum. The storedproteins are stable and inactive inside the cell. The proteins can bereleased, however, by administering a drug (e.g., small molecule ligand)that removes the conditional aggregation domain and thereby specificallybreaks apart the aggregates or clusters so that the proteins may besecreted from the cell. See, Science 287:816-817 and 826-830 (2000).

Other suitable control means or gene switches include, but are notlimited to, the following systems. Mifepristone (RU486) is used as aprogesterone antagonist. The binding of a modified progesterone receptorligand-binding domain to the progesterone antagonist activatestranscription by forming a dimer of two transcription factors which thenpass into the nucleus to bind DNA. The ligand-binding domain is modifiedto eliminate the ability of the receptor to bind to the natural ligand.The modified steroid hormone receptor system is further described inU.S. Pat. No. 5,364,791; WO9640911 and WO9710337.

Yet another control system uses ecdysone (a fruit fly steroid hormone)which binds to and activates an ecdysone receptor (cytoplasmicreceptor). The receptor then translocates to the nucleus to bind aspecific DNA response element (promoter from ecdysone-responsive gene).The ecdysone receptor includes a transactivation domain/DNA-bindingdomain/ligand-binding domain to initiate transcription. The ecdysonesystem is further described in U.S. Pat. No. 5,514,578; WO9738117;WO9637609; and WO9303162.

Another control means uses a positive tetracycline-controllabletransactivator. This system involves a mutated tet repressor proteinDNA-binding domain (mutated tet R-4 amino acid changes which resulted ina reverse tetracycline-regulated transactivator protein, i.e., it bindsto a tet operator in the presence of tetracycline) linked to apolypeptide which activates transcription. Such systems are described inU.S. Pat. Nos. 5,464,758; 5,650,298, and 5,654,168.

Additional expression control systems and nucleic acid constructs aredescribed in U.S. Pat. Nos. 5,741,679 and 5,834,186, to InnovirLaboratories Inc.

In vivo gene therapy may be accomplished by introducing the geneencoding an MK61 polypeptide into cells via local injection of an MK61nucleic acid molecule or by other appropriate viral or non-viraldelivery vectors (Hefti, Neurobiology, 25:1418-1435 (1994)). Forexample, a nucleic acid molecule encoding an MK61 polypeptide may becontained in an adeno-associated virus (AAV) vector for delivery to thetargeted cells (e.g., Johnson, International Publication No. WO95/34670and International Application No. PCT/US95/07178). The recombinant AAVgenome typically contains AAV inverted terminal repeats flanking a DNAsequence encoding an MK61 polypeptide operably linked to functionalpromoter and polyadenylation sequences.

Alternative suitable viral vectors include, but are not limited to,retrovirus, adenovirus, herpes simplex virus, lentivirus, hepatitisvirus, parvovirus, papovavirus, poxvirus, alphavirus, coronavirus,rhabdovirus, paramyxovirus, and papilloma virus vectors. U.S. Pat. No.5,672,344 describes an in vivo viral-mediated gene transfer systeminvolving a recombinant neurotrophic HSV-1 vector. U.S. Pat. No.5,399,346 provides examples of a process for providing a patient with atherapeutic protein by the delivery of human cells which have beentreated in vitro to insert a DNA segment encoding a therapeutic protein.Additional methods and materials for the practice of gene therapytechniques are described in U.S. Pat. No. 5,631,236 involving adenoviralvectors; U.S. Pat. No. 5,672,510 involving retroviral vectors; and U.S.Pat. No. 5,635,399 involving retroviral vectors expressing cytokines.

Nonviral delivery methods include, but are not limited to,liposome-mediated transfer, naked DNA delivery (direct injection),receptor-mediated transfer (ligand-DNA complex), electroporation,calcium phosphate precipitation, and microparticle bombardment (e.g.,gene gun). Gene therapy materials and methods may also include the useof inducible promoters, tissue-specific enhancer-promoters, DNAsequences designed for site-specific integration, DNA sequences capableof providing a selective advantage over the parent cell, labels toidentify transformed cells, negative selection systems and expressioncontrol systems (safety measures), cell-specific binding agents (forcell targeting), cell-specific internalization factors, andtranscription factors to enhance expression by a vector as well asmethods of vector manufacture. Such additional methods and materials forthe practice of gene therapy techniques are described in U.S. Pat. No.4,970,154 involving electroporation techniques; WO96/40958 involvingnuclear ligands; U.S. Pat. No. 5,679,559 describing alipoprotein-containing system for gene delivery; U.S. Pat. No. 5,676,954involving liposome carriers; U.S. Pat. No. 5,593,875 concerning methodsfor calcium phosphate transfection; and U.S. Pat. No. 4,945,050 whereinbiologically active particles are propelled at cells at a speed wherebythe particles penetrate the surface of the cells and become incorporatedinto the interior of the cells.

It is also contemplated that MK61 gene therapy or cell therapy canfurther include the delivery of one or more additional polypeptide(s) inthe same or a different cell(s). Such cells may be separately introducedinto the patient, or the cells may be contained in a single implantabledevice, such as the encapsulating membrane described above, or the cellsmay be separately modified by means of viral vectors.

A means to increase endogenous MK61 polypeptide expression in a cell viagene therapy is to insert one or more enhancer element(s) into the MK61polypeptide promoter, where the enhancer element(s) can serve toincrease transcriptional activity of the MK61 gene. The enhancerelement(s) used will be selected based on the tissue in which onedesires to activate the gene(s); enhancer element(s)known to conferpromoter activation in that tissue will be selected. For example, if agene encoding an MK61 polypeptide is to be “turned on” in T-cells, thelck promoter enhancer element may be used. Here, the functional portionof the transcriptional element to be added may be inserted into afragment of DNA containing the MK61 polypeptide promoter (andoptionally, inserted into a vector and/or 5′ and/or 3′ flankingsequence(s), etc.) using standard cloning techniques. This construct,known as a “homologous recombination construct”, can then be introducedinto the desired cells either ex vivo or in vivo.

Gene therapy also can be used to decrease MK61 polypeptide expression bymodifying the nucleotide sequence of the endogenous promoter(s). Suchmodification is typically accomplished via homologous recombinationmethods. For example, a DNA molecule containing all or a portion of thepromoter of the MK61 gene(s) selected for inactivation can be engineeredto remove and/or replace pieces of the promoter that regulatetranscription. For example the TATA box and/or the binding site of atranscriptional activator of the promoter may be deleted using standardmolecular biology techniques; such deletion can inhibit promoteractivity thereby repressing the transcription of the corresponding MK61gene. The deletion of the TATA box or the transcription activatorbinding site in the promoter may be accomplished by generating a DNAconstruct comprising all or the relevant portion of the MK61 polypeptidepromoter(s) (from the same or a related species as the MK61 gene(s) tobe regulated) in which one or more of the TATA box and/ortranscriptional activator binding site nucleotides are mutated viasubstitution, deletion and/or insertion of one or more nucleotides. As aresult, the TATA box and/or activator binding site has decreasedactivity or is rendered completely inactive. The construct willtypically contain at least about 500 bases of DNA that correspond to thenative. (endogenous) 5′ and 3′ DNA sequences adjacent to the promotersegment that has been modified. The construct may be introduced into theappropriate cells (either ex vivo or in vivo) either directly or via aviral vector as described herein. Typically, the integration of theconstruct into the genomic DNA of the cells will be via homologousrecombination, where the 5′ and 3′ DNA sequences in the promoterconstruct can serve to help integrate the modified promoter region viahybridization to the endogenous chromosomal DNA.

Additional Uses of MK61 Nucleic Acids and Polypeptides

Nucleic acid molecules of the present invention (including those that donot themselves encode biologically active polypeptides) may be used tomap the locations of the MK61 gene and related genes on chromosomes.Mapping may be done by techniques known in the art, such as PCRamplification and in situ hybridization.

MK61 nucleic acid molecules (including those that do not themselvesencode biologically active polypeptides), may be useful as hybridizationprobes in diagnostic assays to test, either qualitatively orquantitatively, for the presence of an MK61 DNA or corresponding RNA inmammalian tissue or bodily fluid samples.

The present invention thus provides reagents for use in diagnosticapplications. The human MK61 gene has been localized to chromosome band19q13. More specifically, the gene locates to a region within, or closeto, 19q13.1. Several other genes of interest have been localized to thisregion of chromosome 19, including the human leukocyte receptor cluster(LRC) which has been demonstrated to contain 19 genes encodingleukocyte-expressed receptors of the immunoglobulin (Ig) superfamily,the human Kir2.4 inwardly rectifying potassium channel gene (KCNJ14),the human killer cell inhibitory receptor gene KIR103, the ribosomalprotein S19 gene, prostase, and Protease Serine-Like 1. MK61 is acandidate for the diseases and disorders recited herein includingCystinuria, Congenital nephrotic syndrome, Familial nephrotic syndrome,Familial focal segmental glomerulosclerosis, familial Wilms tumor FWT2,B-cell lymphoma-associated hemophagocytic syndrome, Camurati-Engelmanndisease, progressive diaphyseal dysplasia, hereditary spasticparaplegia, asthma, heart defects, eye development, systemic lupuserythematosus (hSLE1), primary microcephaly (MCPH2), autosomal recessivespondylocostal dysostosis, cystic fibrosis modifier locus for meconiumileus, acute myelogenous leukemia, B-cell lymphoma associated withhaemophagocytic syndrome, multiple myeloma, testicular germ cell tumors,malignant glioma, familial benign hypercalcemithus, the MK61 gene, aprobe comprising MK61 DNA or RNA can be used to determine if the MK61gene is present on chromosome 19, or if a mutation has occurred.Detectable chromosomal aberrations at the MK61 gene locus include, butare not limited to, aneuploidy, gene copy number changes, insertions,deletions, restriction site changes and rearrangements. Theseaberrations can occur within the coding sequence, within introns, orwithin flanking sequences, including upstream promoter and regulatoryregions, and may be manifested as physical alterations within a codingsequence or changes in gene expression level. Analytical probes willgenerally be at least 20 nucleotides in length, although somewhatshorter probes (14-17 nucleotides) can be used. PCR primers are at least5 nucleotides in length, preferably 15 or more nucleotides, morepreferably 20-30 nucleotides in length. Short polynucleotides can beused when a small region of the gene is targeted for analysis. For grossanalysis of genes, a polynucleotide probe may comprise an entire exon ormore. Probes will generally comprise a polynucleotide linked to asignal-generating moiety such as a radionucleotide. In general, thesediagnostic methods comprise the steps of (a) obtaining a genetic samplefrom a patient; (b) incubating the genetic sample with a polynucleotideprobe or primer as disclosed above, under conditions wherein thepolynucleotide will hybridize to complementary polynucleotide sequence,to produce a first reaction product; and (c) comparing the firstreaction product to a control reaction product. A difference between thefirst reaction product and the control reaction product is indicative ofa genetic abnormality in the patient. Genetic samples for use within thepresent invention include genomic DNA, cDNA, and RNA. The polynucleotideprobe or primer can be RNA or DNA, and will comprise a portion of SEQ IDNO:1, SEQ ID NO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11,SEQ ID NO:13, or SEQ ID NO:15, the complement of SEQ ID NO:1, SEQ IDNO:3, SEQ ID NO:5, SEQ ID NO:7, SEQ ID NO:9, SEQ ID NO:11, SEQ ID NO:13,or SEQ ID NO:15, or an RNA equivalent thereof. Suitable assay methods inthis regard include molecular genetic techniques known to those in theart, such as restriction fragment length polymorphism (RFLP) analysis,short tandem repeat (STR) analysis employing PCR techniques, ligationchain reaction (Barany, PCR Methods and Applications 1:5-16 (1991)),ribonuclease protection assays, and other genetic linkage analysistechniques known in the art. See Sambrook et al., Id.; Ausubel et. al.,Id., and A. J. Marian, Chest 108:255-65 (1995). Ribonuclease protectionassays (Ausubel et al., Id., ch. 4) comprise the hybridization of an RNAprobe to a patient RNA sample, after which the reaction product(RNA-RNA) hybrid) is exposed to RNase. Hybridized regions of the RNA areprotected from digestion. Within PCR assays, a patient genetic sample isincubated with a pair of oligonucleotide primers, and the region betweenthe primers is amplified and recovered. Changes in size, amount, orsequence of recovered product are indicative of mutations in thepatient. Another PCR-based technique that can be employed is singlestrand conformational polymorphism (SSCP) analysis. See Hayashi, PCRMethods and Applications 1:34-38 (1991).

Assays for MK61 protein in serum may be used to detect the diseases anddisorders recited herein. Those skilled in the art will recognize thatconditions related to MK61 underexpression or overexpression may beamenable to treatment by therapeutic manipulation of MK61 proteinlevels.

The MK61 polypeptides may be used (simultaneously or sequentially) incombination with one or more cytokines, growth factors, antibiotics,anti-inflammatories and/or chemotherapeutic agents as is appropriate forthe indication being treated.

Other methods may also be employed where it is desirable to inhibit theactivity of one or more MK61 polypeptides. Such inhibition may beeffected by nucleic acid molecules which are complementary to and whichhybridize to expression control sequences (triple helix formation) or toMK61 mRNA. For example, antisense DNA or RNA molecules, which have asequence that is complementary to at least a portion of the selectedMK61 gene(s) can be introduced into the cell. Anti-sense probes may bedesigned by available techniques using the sequence of MK61 polypeptidedisclosed herein. Typically, each such antisense molecule will becomplementary to the start site (5′ end) of each selected MK61 gene.When the antisense molecule then hybridizes to the corresponding MK61mRNA, translation of this mRNA is prevented or reduced. Anti-senseinhibitors provide information relating to the decrease or absence of anMK61 polypeptide in a cell or organism.

Alternatively, gene therapy may be employed to create adominant-negative inhibitor of one or more MK61 polypeptides. In thissituation, the DNA encoding a mutant polypeptide of each selected MK61polypeptide can be prepared and introduced into the cells of a patientusing either viral or non-viral methods as described herein. Each suchmutant is typically designed to compete with endogenous polypeptide inits biological role.

In addition, an MK61 polypeptide, whether biologically active or not,may be used as an immunogen, that is the polypeptide contains at leastone epitope to which antibodies may be raised. Selective binding agentsthat bind to an MK61 polypeptide (as described herein) may be used forin vivo and in vitro diagnostic purposes, including but not limited to,use in labeled form to detect the presence of MK61 polypeptide in a bodyfluid or cell sample. The antibodies may also be used to prevent, treator diagnose a number of diseases and disorders, including those recitedherein. The antibodies may bind to an MK61 polypeptide so as to diminishor block at least one activity characteristic of an MK61 polypeptide, ormay bind to a polypeptide to increase at least one activitycharacteristic of an MK61 polypeptide (including by increasing thepharmacokinetics of the MK61 polypeptide).

The following examples are intended for illustration purposes only andshould not be construed as limiting the scope of the invention in anyway.

EXAMPLE 1 Isolation of Human MK61 cDNA Clones

A TNF receptor family profile search of the Amgen EST database wasperformed. One human EST sequence (G-0042-B7) was identified as apossible member of the TNF receptor family name as MK61. The full-lengthhuman clone was subsequently PCR amplified from a human lymphnodelibrary using the following primers: human MK61 sense primer(5′-GGTGACCACCTCGTGGGCAACGTCT-3′; SEQ ID NO: 21), antisense primer(5′-GCCCAATTAGGATTGTACAAGAAG-3; SEQ ID NO: 22) under standard conditionsknown in the art. Poly (A)+ RNA from the human lymph node wasreverse-transcribed, and the cDNAs were synthesized using the Smart RACEcDNA amplification Kit (Clontech , Palo Alto, Calif.) according to themanufacturer's instructions. The full-length cDNA of the human MK61 genewas cloned into the pcDNA3 vector for mammalian cell expression(Invitrogen, Carlsbad, Calif.) and sequenced using standard methods. Thename of the clone is pcdna3huMK61#5 and it contains the human MK61 T1isoform cDNA.

The human MK61 cDNA sequence is 1668 nucleotides (SEQ ID NO: 1) andencodes a 355 amino acid polypeptide (SEQ ID NO: 2). The polypeptide(denoted herein as hMK61T1; see FIG. 1) contains a signal peptidespanning residues 1-23, a cysteine rich domain spanning residues 26-60that matches the TNFR superfamily cysteine-rich region signature (Madryet al. INTERNATIONAL IMMUNOLOGY. 10:1693-1702, 1998, and referencestherein), a transmembrane domain spanning residues 157-185, and a longintracellular domain. Careful alignment of all available human MK61matching cDNA and genomic sequences available in public databases, Amgeninternal databases, and the Celera database, identified five additionalfull length human MK61 isoforms (denoted herein as human MK61T2, MK61T3,MK61T4, MK61T5, and MK61T6).

hMK61T2 polynucleotide sequence is 1525 nucleotides (SEQ ID NO: 3) andencodes a polypeptide of 85 amino acids (SEQ ID NO: 4) containing asignal peptide(residues 1-23) but not a predicted transmembrane domain,suggesting that this isoform may encode a secreted polypeptide (FIG. 2).hMK61T2 contains cysteine rich domain spanning residues 26-51 thatexhibit an imperfect match (5 out of 6 cysteine match) to the TNFRsuperfamily cysteine-rich region signature. hMK61T3 polynucleotidesequence is 1289 nucleotides (SEQ ID NO: 5) and encodes a 136 amino acidresidue polypeptide (SEQ ID NO: 6) containing a signal peptide (residues1-23) but not contain a predicted transmembrane domain, suggesting thatthis isoform may encode a secreted polypeptide (FIG. 3). hMK61T3contains a cysteine rich domain spanning residues 26-60 that matches theTNFR superfamily cysteine-rich region signature. hMK61T4 polynucleotidesequence is 1164 nucleotides (SEQ ID NO:7) and encodes a 187 amino acidresidues polypeptide (SEQ ID NO: 8) containing a signal peptide(residues 1-23) but not a predicted transmembrane domain, suggestingthat this isoform may encode a secreted polypeptide (FIG. 4). hMK61T4contains cysteine rich domain spanning residues 26-51 that exhibit animperfect match (5 out of 6 cysteine match) to the TNFR superfamilycysteine-rich region signature. hMK61T5 polynucleotide sequence is 1483nucleotides (SEQ ID NO: 9) and encodes encodes an 71 amino acid residuespolypeptide (SEQ ID NO: 10) with a signal peptide (residues 1-23) butnot a predicted transmembrane domain, suggesting that this isoform mayencode a secreted polypeptide (FIG. 5). hMK61T5 contains a cysteine richdomain spanning residues 26-57 that matches the TNFR superfamilycysteine-rich region signature but varies slightly from that of hMK61T1.hMK61T6 polynucleotide sequence is 1104 nucleotides (SEQ ID NO: 11) andencodes a 167 amino acid residues polypeptide (SEQ ID NO: 12) containinga signal peptide (residues 1-23) but not a predicted transmembranedomain, suggesting that this isoform may encode a secreted polypeptide(FIG. 6). hMK61T6 contains cysteine rich domain spanning residues 26-51that exhibit an imperfect match (5 out of 6 cysteine match) to the TNFRsuperfamily cysteine-rich region signature.

Interestingly all the human MK61 isoforms contain a complete or partialTNFR-type cysteine rich domain which may constitute part of theligand-binding domain. Hence, while hMK61T1 appears to encode a bonafide novel TNFR family member cell-surface receptor, human isoformsMK61T2-T6 appear to encode secreted receptors. Secreted receptors mayfunction as decoy-receptors which prevent the unknown MK61 ligand frominteracting with its receptor as it was previously demonstrated forOsteoprotegerin (OPG).

Osteoprotegerin ligand is a cytokine that regulates osteoclastdifferentiation and activation. (Lacey et al. Cell:93: 165-176, 1998).In addition, the MK61T1-T6 isoforms may bind and regulate reversesignaling through the unknown MK61 ligand.

EXAMPLE 2 Isolation of Murine MK61 cDNA Clone

A TNF receptor family profile search of the Amgen EST database wasperformed as described above in Example 1. One human EST sequence(G-0042-B7) was identified as a possible member of the TNF receptorfamily name as MK61. The full-length murine MK61 clone was PCR amplifiedfrom a mouse A20 cell library using the following primers: mouse senseprimer (5′CGGACGCGTGGGCGGACGCGTGGG-3′ SEQ ID NO: 23) antisense primer(5′-AGCAAACTCTGACTCAGCCAAGTT-3′; SEQ ID NO: 24) under standardconditions known in the art. Poly (A)+ RNA from the mouse B lymphomacell line A20 was reverse-transcribed, and the cDNA was synthesizedusing the Smart RACE cDNA amplification Kit (Clontech, Palo Alto,Calif.) according to the manufacturer's instructions. The full-lengthcDNA of the mouse gene was cloned into the pcDNA3 vector for mammaliancell expression (Invitrogen, Carlsbad, Calif.) and sequenced usingstandard methods.

The murine MK61 polynucleotide sequence is 1202 nucleotides (SEQ ID NO:13) and encodes a 345 amino acid polypeptide(SEQ ID NO:14). The murineMK61T1 polypeptide is a cell surface receptor which has a signalsequence spanning residues 1 to 21 and a transmembrane domain (FIG. 7).

EXAMPLE 3 Tissue Distribution of hMK61 mRNA

MK61 mRNA distribution was determined by Northern blot analysis andquantitative PCR. Human peripheral blood T cells, B cells and monocyteswere purified by Rosette Sep enrichment cocktail (Stem CellTechnologies) according to the manufacturer's instructuions. HumanBurkitt's Lymphoma cells, Raji cells, T lymphoma cells, Jukat cells,K562 cells and U937 cells were obtained from the ATCC (Rockville, Md.).Total RNA was isolated from these cells by the Rneasy Kit (Qiangen,Valencia, Calif.) according to the manufacturer's instructions.

Northern blots analysis was performed using standard conditions known inthe art. Multiple tissue Northern blot and multiple tissue cDNAs werepurchased from Clontech (Palo Alto, Calif.). The Northern blots werehybridized with random primed human and mouse MK61 radioactive probesfor 3 hours at 55° C., and then washed with several changes of2×SSC/0.1% SDS followed by 0.1×SSC/0.1% SDS for 30 minutes.

The Northern blot analysis demonstrated that hMK61 was predominantlyexpressed in peripheral lymphoid organs, spleen, lymph nodes, thymus,bone marrow, in peripheral blood leukocytes, as well as in fetal liver.(See FIGS. 13 and 14) Several different MK61 isoforms were expressed inthose organs but the major transcipt was 1.6 kbp.

Real-time quantitative PCR was carried out on various human tissues andcell lines. This assay uses a fluorogenic probe and PCR primers toenable the detection of a specific PCR product. The PCR primers and theprobe were designed using PE Biosystems' Primer Express software andwere synthesized by Amgen Boulder as requested. Oligonucleotide primersspecific and probes for human MK61 (Probe #2288-23 ETT CCC AGT TTT TCATCT GCA CTG CCA X (SEQ ID NO: 40);5′ primer #2288-22 TGC TGG ACC CAA CACAAA TG (SEQ ID NO: 41); 3′ primer #2288-24 TGC CAT CCA ACC ACT CAG TC(SEQ ID NO: 42))and human cyclophilin (Probe #2661-92 ECT GCC TGC TGCCTG GTC CAC CTX (SEQ ID NO: 43), 5′ primer #2661-90 ACA CCT GGC CGC AAGATA TG (SEQ ID NO: 44); 3′ primer: #2661-91 GAC TCG GCC TCA GCG AAT AG(SEQ ID NO: 45)) were used as primers for Taqman Following the PEBiosystems' standard protocol, the Taqman PCR reactions were performedon ABI PRISM 7700 instrument and the data were analyzed by PEBiosystems's Sequence Detection System software (See FIG. 15)

Human MK61 mRNA expression was the greatest in monozytic cells, B cells,lymph nodes, spleen and T cells. Intermediate levels of human MK61 mRNAexpression were detected in liver, bone marrow, thymus, tonsil, andfetal liver. Low levels of human MK61 mRNA were detected in lung,placenta and Jurkat cells. Interestingly, the expression of human MK61mRNA was higher in primary B cells, T cells and monozytic cells than inthe corresponding tumor cells lines Raji, K562 and U937. This expressionpattern would be consistent with the notion that MK61 expression islymphoid-specific and may be downregulated in tumor cells.

EXAMPLE 4 Preparation of the mMK61-Fc Fusion Construct

The predicted 175 amino acid extracellular portion of Smil2-00051-f3 wassubcloned into the PEFBOS vector (pEF-BOS; a powerful mammalianexpression vector; Mizushima et al. Nuc. Acids Res. 18: 5322, 1990), andan Fc portion was attached at the end of the gene. The nucleotidesequence encoding the mMK61-Fc is set out as SEQ ID NO: 15. Transfectionwas performed using Bio-Rad Cytofectene as a transfection reagent. Thecondition medium was collected 48 hours after the transfection, and CMwas 10× concentrated by Centricon 10 columns (Millipore Corp., Bedford,Mass.). The samples loaded in lanes 6, 7, and 8 were the concentratedconditioned media (See FIG. 9).

The mMK61 Fc fusion protein (SEQ ID NO: 16) was detected by ananti-human IgG(Fc) (Pierce), at a dilution of 1:3000, and thenvisualized by enhanced chemical luminescence (ECL). The exposure timewas 15 seconds. 2933 cell lysate was used as a positive control and wasprepared as follows: 293 cells (available under ATCC Accession NumberCRL-1573) were suspended in 200 μl 2×SDS loading buffer, and wereheated. The cell lysates (5 μl) was then loaded into each lane. TheWestern blot (FIG. 9) indicates that the MK61-Fc fusion protein wassecreted and is detectable in the cellular conditioned media.

EXAMPLE 5 Production and Purification of Recombinant MK61-Fc FusionProteins

A. Cloning and Bacterial Expression of Human MK61-Fc protein:

PCR amplification employing the primer pairs and templates describedbelow were used to generate various forms of human MK61 proteins. Oneprimer of each pair introduced a stop codon (TAA). and a unique XhoIsite following the carboxy terminus of the gene. The other primer ofeach pair introduced a unique NdeI site, an N-terminal methionine, andoptimized codons for the amino terminal portion of the gene. PCR andthermocycling were performed using standard recombinant DNA methodology.The PCR products were purified, restriction digested, and inserted intothe unique NdeI and XhoI sites of vector pAMG21 (ATCC accession no.98113). Subsequently, prototrophic E. coli strains 393 or 2596 weretransformed with the vector. Other commonly used E. coli expressionvectors and host cells are also suitable for expression. Aftertransformation, the clones were selected, plasmid DNA was isolated andthe sequence of the MK61 protein insert were confirmed.

1. pAMG21-Human MK61 21-160 His:

The pAMG21-h MK61 21-160 His construct was engineered to be 147 aminoacids in length and have the following N-terminal and C-terminalresidues: NH₂-Met-Glu-Ala-Ser-Gln - - -Gln-Ala-Trp-Pro-Asn-His-His-His-His-His-His-COOH (SEQ ID NO: 25). Thefollowing oligonucleotides primer pair (#2609-87 and #2609-88) was usedfor PCR and cloning this gene construct (2609-87: 5′-GAG GAA TAA CAT ATGGAA GCC TCT CAG TAT TGC GGC CGC-3′ (SEQ ID NO: 26); 2609-88: 5′-CGG CCGATC CTC GAG TTA ATG ATG ATG ATG ATG ATG ATT CGG CCA GGC CTG CTG-3′(SEQID NO: 27)).

2. pAMG21-Human MK61 21-160 Fc (Human IgG1)

The pAMG21-human MK61 21-160 Fc construct was engineered to be 373 aminoacids in length and have the following N-terminal and C-terminalresidues: NH₂-Met-Glu-Ala-Ser-Gln - - - Ser-Pro-Gly-Lys-COOH (SEQ ID NO:28). A linker composed of five glycine residues was inserted between theC-terminus of the MK61 protein and the N-terminus of human IgG1 Fc. Thesequence of the MK61-Fc junction was as follows:Gln-Ala-Trp-Pro-Asn-Gly-Gly-Gly-Gly-Gly-Asp-Lys-Thr-His (SEQ ID NO: 29).PCR amplification of this construct was performed in two steps. In thefist step, the MK61 and Fc portions of the gene were amplified. Oligos#2609-87 (5′-GAG GAA TAA CAT ATG GAA GCC TCT CAG TAT TGC GGC CGC-3′ SEQID NO: 30); and #2609-97 (5′-ACA TGT GTG AGT TTT GTC ACC ACC ACC ACC ACCATT CGG CCA GGC CTG CTG-3′SEQ ID NO: 31) were used to amplify the MK61portion. Oligos #2609-98 (5′-CAG CAG GCC TGG CCG AAT GGT GGT GGT GGT GGTGAC AAA ACT CAC ACA TGT-3′ SEQ IS NO: 32) and #2293-10 (5′-CCG CGG ATCCTC GAG TTA TTT ACC CGG AGA CAG GGA GAG-3′ SEQ ID NO: 33) were used toamplify the human IgG1 fc portion. In the second step, the reactionproducts from the first amplification were gel purified and used astemplates to create the final MK61::fc construct. Oligos #2609-87 (SEQID NO: 30) and #2293-10 (SEQ ID NO: 33) were used for PCR amplificationof this construct.

After confirmation of the DNA sequence, the transformed E. coli weregrown at 37° C. to mid-log phase and treated with homoserine lactone(HSL) at a final concentration of 250 ng/ml to induce expression ofMK61-Fc fusion protein. Following induction, the cells were grown at 37°C. for several hours and subsequently harvested by centrifugation andfrozen at −80° C. Growth of the transfected E. coli, induction ofMK61-Fc protein expression and isolation of inclusion bodies containingMK61-Fc was carried out according to procedures described in U.S. patentapplication Ser. No. 08/577,788 filed Dec. 22, 1995 incorporated hereinby reference.

Purification and refolding of the MK61-Fc fusion protein expressed in E.coli was accomplished using the following methods. To solubilize theMK61-Fc fusion protein, the bacterial cells were broken in amicrofluidizer and centrifuged at 12,000 g for 1 hour. The resultinginclusion bodies were washed with water and centrifuged at 12,000 g for1 hour. The pellet was then solubilized for 1 hour in 50 mM Tris, 8 MGuHCl and 7 mM DTT (pH 8.5) and centrifuged at 12,000 g for 1 hour.

To refold the MK61-Fc fusion protein, the supernanant was diluted 1:20with 50 mM Tris, 2 M Urea, 0.2 M arginine (pH 8.5) and incubated at 4°C. until the Elman test was negative for free thiol (approximately 4days). The supernatant was then concentrated 20 fold and diafilteredwith 4 volumes of 50 mM Tris (pH 8.5). The diluted supernatant was acidprecipitated by diluting the solution 10 fold with 25 mM Tris (pH 8.5)and lowering the pH to 5.0. The diluted solution was then stirred for 5minutes and centrifuged at 12,000 g for 30 minutes.

For purification, the supernatant was loaded onto a SP high performancecolumn and run on a 0-600 mM NaCL gradient in the presence of NaOAc (pH5.0) over 60 column volumes. The fusion protein eluted at around 500 mMNaCl. Pooled fractions were titrated to pH 7.0, brought up to aconcentration of 1M in ammonium sulfate (AS) and centrifuged at 12,000 gfor 30 minutes. The supernatant was then loaded onto a butyl highperformance column and run on a gradient of 1M AS to 0M AS in thepresence of 10 mM NaPi (pH 7.0) over 50 column volumes. The fusionprotein eluted approximately at 30 mM AS. The pooled fractions werediafiltered into PBS.

B. Cloning, Expression and Purification of MK61-Fc in Mammalian CellCulture:

A cDNA fragment encoding human MK61-Fc amino acids 1 to 153 wasamplified by PCR using the pcdna3huMK61#5 as a template and the primers#2623-81 (CAG CCC AAG CTT TAG ACC ACC ATG GGG CCT GGA CGA TGC; SEQ IDNO: 34) and 2623-83 (CAG GTC GAC AGG CTC AGG GGT CCT; SEQ ID NO: 35).These primers inserted HindIII and Sal1 sites at the 5′ and 3′ end ofthe gene respectively. PCR product were purified, digested with HindIIIand Sal1 and ligated into huOPG194 Fc delta C vector, 9described in WO01/18203 and in EP1127117), digested with HindIII and Sal1 anddephosphorylated. The products of the ligation were transformed intoDH5α competent cells (Invitrogen, Carlsbad, Calif.) and plated onto LB+ampicillin plates.

Eight colonies of the transformed DHα competent cells were grown toisolate DNA using the mini-prep technique (Qiagen) The isolated DNA wasscreened by digestion with Not1 and Pvu1. Five of the clones generated a1512 base pair fragment as expected. Clones 1 and 7 of the positiveclones were amplified in 500 ml preparations, the DNA isolated andsequenced using standard methods.

The DNA isolated from clone 7 was the correct sequence. The amino acidsequence of MK61-Fc is shown in FIG. 24 as SEQ ID NO: 36. Clone 7 DNA(15 μg) was linearized with Pvu1 and transfected into AM-1/D cells.AM-1/D are Chinese Hamster Ovary cells devoid of DHFR (Urlaub and Chasin1980 PNAS vol 77 4216-4220) adapted to serum free conditions (describedin U.S. Pat. NO. 6,210,924). Stable clones were generated based on theselection marker DHFR (dihydrofolate reductase). Nine stable clones wereexpanded for expression analysis. Expression of MK61-Fc was determinedby Western-blotting, using anti-human IgG1 Fc antibodies (Pierce). Ahigh-expressing clone was selected and expanded by growing the cells inroller bottles using standard methods.

To purify human MK61-Fc fusion protein, conditioned CHO-MK61-Fc mediawas loaded onto a protein G column equilibrated in PBS. The column waswashed with 20 column volumes of PBS and the fusion protein was elutedwith 100 mM Glycine (pH 2.6), and the pooled fractions were neutralizedwith 1 M Tris (pH 8.5) and diafiltered into PBS.

C. Production of Murine Mk61/Fc Delta C Fusion Protein:

The murine MK61 cDNA encoding the extracellular domain of the proteinwas amplifed from the full-length muMK61 cDNA (SEQ ID NO: 13) usingprimers #2664-83 (CAG CCC AAG CTT TAG ACC ACC ATG GGG CCC AGC TGG CTT;SEQ ID NO: 37) and #2664-84 (CAG GTC GAC CTC ATT CTT GGT TGT; SEQ ID NO:38). These primers inserted HindIII and Sal1 sites at the 5′ and 3′ endof the gene respectively. The PCR product was purified, digested withHindIII and Sal1 and ligated into huOPG194 Fc delta C vector digestedwith HindIII and Sal1 and dephosphorylated. The ligation product wastransformed into DH5α competent cells and plated onto LB+ ampicillianplates.

Sixteen colonies of transformed DHα competent cells were grown toisolate their DNA by the mini-prep technique. The isolated DNA wasscreened by digestion with MSC1 (unique enzyme for MK61) and Pvu1(unique enzyme for pDSRα vectors). Fifteen of the clones generated a1523 base pair fragment as expected. Clones 2 and 4 of these positiveclones were amplified in 500 ml preps; DNA isolated and sequenced usingstandard methods.

The DNA isolated from both clones 2 and 4 had the correct sequence forexpression of MK61-Fc fusion protein (FIG. 25; SEQ ID NO: 39). Clone 2DNA (15 μg) was linearized with Pvul and transfected in to AM-1/D cellswhich are derived from the Chinese Hamster Ovary (CHO) cell-line. Stableclones were generated based on the selection marker DHFR. Nine cloneswere expanded for expression analysis. Expression of MK61-Fc wasdetermined by Western-blotting, using anti-human Fc antibodies.

EXAMPLE 6 MK61-Fc Binding as Determined by FACS Analysis

Binding of the MK61-Fc proteins was detected on human cells byflorescent activated cell sorting (FACS). Raji, Molt-4, U937, K562, A20and Jurkat cells were obtained from the ATCC. The cells were collectedand incubated at room temperature with 1 μg/ml of human MK61-Fc inbinding buffer (DMEM medium containing 10 mM HEPES buffer, 2% goatserum, 5% rabbit serum, 1 μg/ml anti-mouse CD16/CD32 monclonal antibody(PharMingen, San Diego, Calif.)) for 30 minutes followed by 3 washeswith PBS containing 2% FBS. Binding of the MK61-Fc fusion proteins tothe cell surface was assessed by immunofluorescent staining using FITCconjugated anti-human IgG Fc secondary antibody (PharMingen, San Diego,Calif.). Fluorescence was detected using a FACStar (Becton andDickinson, Mountain View, Calif.).

MK61-Fc binding was detected on U937 and Jurkat cells. (See FIG. 16) Toenhance the MK61-Fc binding, U937 and Jurkat cells were treated withhuman interferon gamma (10 ng/ml) for 24 hours prior to analysis. Thepre-treatment with interferon gamma enhanced MK61-Fc binding. (See FIG.17) The binding of MK61-Fc fusion protein to these cells indicates thatthe MK61 ligand exists on the cell surface of monozytic (U937) and Tcells (Jurkat).

The existence of the unknown MK61 ligand on the surface of immune cellssuggests that ligand binding soluble forms of MK61 (such as MK61-Fcfusion protein) may act as “positive reagents” which activate the MK61receptor signaling pathway. This may be accomplished by the positivereagents binding to the yet unknown MK61 ligand(s) located on thesurface of the immune cells and thereby triggering reverse signalingthrough the ligand. Such signaling would be the immune system regulatingevent resulting in lymphocyte expansion and immunoglobulin production

EXAMPLE 7 MK61-Fc Inhibited Immunoglobulin Production in PrimarySplenocytes

Total spleen cells were isolated from mice spleens using lymphocyteseparation medium (ICN, Aurora, Ohio) centrifugation. Splenocytes werecultured in vitro with 150 ng/ml lipo-poly-saccraride (LPS) for 72-96hours in the presence of mouse or human delta C MK61-Fc delta fusionprotein. Subsequently, the culture supernatants from the treated cellswere removed after 4 days to analyze the production of various Igisotypes. (PharMingen, Ca).

Treatment with both murine and human MK61-Fc fusion proteins caused adose-dependent decrease in IgA and IgG production in the mousespleenocyte cultures (See FIG. 18). Maximum inhibition was achieved whenMK61-Fc was used at a concentration of 100 ng/ml. This data indicatesthat MK61-Fc fusion protein is a potent inhibitor of the immune system.This data also suggests that the MK61 receptor activates the immunesystem signaling pathway that may be antagonized by “negativesregulators” such as the soluble MK61-Fc fusion protein.

To determine if the MK61-Fc fusion protein-induced inhibition ofimmunoglobulin production was due to inhibition of B cell proliferation,the effect of MK61-Fc on B cell proliferation was measured. Mouse Bcells were purified by negative selection from spleens of C57Bl/6 miceusing a mouse B cell recovery column (Cedarlane, Hornby, Ontario,Canada). The cells isolated by this method were more than 90% positivefor B220 staining as determined by FACS analysis. 1×10⁶/ml were seededin 96 well flat bottom tissue culture plates in medium (RPMI-1640, 5%FBS, 5×10⁻⁵M 2ME, 2 μg/ml of affinity-purified goat F (ab′)₂ anti-mouseIgM). The B cells were then incubated with 100 ng/ml human or mouseMK61-Fc protein in the presence or absence of increasing amounts ofCD40L, APRIL or TALL-1 for 72 hours. DNA synthesis was quantitated bymeasuring the incorporation of [³H ]thymidine. 0.5 μCi of [³H ]thymidinewas added 18 hours prior to harvesting the cells and counting theincorporation of [³H] thymidine. Treatment with MK61-Fc fusion proteinsdid not effect B cell proliferation in this assay.

EXAMPLE 8 Effect of MK61-Fc Fusion Protein Treatment on B Cell ResponsesIn Vivo

To characterize the functional significance of the MK61 polypeptide, thefusion protein MK61-Fc delta C used to treat mice.

Initially, Balb/c mice (females of 8-12 weeks of age, Charles RiverLaboratories) were treated interperitoneally with 5 mg/Kg of MK61-Fconce a day for seven consecutive days starting on day 0. Control micewere treated with 5 mg/Kg of IgG1 Fc or saline as above. Mice weresacrificed one day following the last injection of MK61-Fc, i.e., on day7. The spleens were dissected for histological examination, FACSanalysis and for serum Ig measurements.

A. Histological Analysis:

For histological examination, spleens were fixed in formalin, embeddedin paraffin following standard procedures, and stained with hematoxylinand eosin. Treatment with MK61-Fc fusion protein increased spleen weightby 75% compared to control Fc protein or saline (FIG. 19, top panel).The spleen weight increase reflects a comparable increase in the numberof spleen lymphocytes (FIG. 19, bottom panel). The total number oflymphocytes was determined using a Technicon H.I.E. Counter (Bayer Co.Diagnostic Division, Northwood, Md.) following the standard procedurerecommended by the manufacturer. The histological examination of thespleens from the MK61-Fc-treated mice indicated the presence of lymphoidhyperplasia, characterized by (1) increased numbers of moderately- towell-developed follicular germinal centers as well as (2) increasednumbers of plasma cells that were usually located in focal accumulationsat the interface between the white and red pulp (See FIG. 20). Lymphoidhyperplasia was not observed in Fc-protein or saline-treated controlmice.

B. FACS Analysis

For FACS analysis, spleens were collected in saline and homogenized toyield a cell suspension. The total lymphocyte number was obtained with acell counter, while lymphocyte subset percentages were derived byimmunofluorescence double staining and flow cytometry. MK61-Fc fusionprotein increased the total number of spleen lymphocytes compared tocontrol Fc or saline by 90% (FIG. 21 top panel). MK61-Fc proportionallyincreased T, B, and non-T non-B cells. In fact, MK-61-Fc increased theabsolute numbers of CD3+ (T cells), CD3−/B220+ (B cells), and CD3−/B220−(non-T and non-B cells) cells but did not significantly affect thepercentages of these cells (FIG. 21 bottom panel). MK61-Fc modified theproportions of B cell subsets. In fact, MK61-Fc decreased the percentageof CD19+/CD5+ (B) cells but still increased their absolute number (FIG.21).

C. Serum Immunoglobin Measurements:

Serum immunoglobins were measured by sandwich ELISA as previouslydescribed (Guo et al. J. Immunol. 166: 5578-84, 2001). Compared tocontrol Fc, MK61-Fc increased the serum concentrations of total IgG,IgG1, and IgG2b but did not significantly modify the concentrations ofother Ig types and subtypes (FIG. 22). The increase in IgG1 was the mostpronounced if all IgG subtypes (by about 6 fold).

EXAMPLE 9 Additional Effects of MK61-Fc Fusion Protein Treatment on TCell Response In Vivo

In another in vivo experiment, mice were immunized on day 0, prior tothe first injection of murine MK61-Fc fusion protein or FC-proteincontrol, with the T cell independent antigen Pneumovax (115 μg, Merck,West Point, Pa.) or the T cell dependent antigen keyhole limpethemocyanin (KLH, Pierce, Rockford, Ill.) in complete Freund's adjuvant(CFA). Following the pre-treatment, the animals were treated asdescribed above in Example 7. The mice were bled on days 7 and 14 toobtain serum to measure antigen-specific antibodies.

Anti-KLH and anti-Pneumovax IgG and IgM were measured in serum by ELISAas previously described (Yu et al. Nature Immunol. 1: 252-256, 2000)Briefly, for the measurement of anti-KLH, plates were coated with KLH inPBS, blocked, and various dilutions of standard and test samples wereadded. Captured anti-KLH IgG or IgM were revealed using anti-IgG oranti-IgM biotinylated antibodies and neutravidin-conjugated HRP(horse-radish peroxidase). For the measurement of anti-Pneumovax IgM,plates were coated with Pneumovax using poly-L-lysine, blocked, andvarious dilutions of standard and test samples were added. Capturedanti-Pneumovax IgM were revealed using an anti-IgM biotinylated antibodyand neutravidin-conjugated HRP

Compared to control Fc-protein, MK61-Fc fusion protein did not changethe serum concentration of anti-Pneumovax antibodies (IgM; data notshown); but changed that of anti-KLH antibodies of certain Ig classesand subclasses (See FIG. 23). On days 7 and/or 14 of immunization,MK61-Fc fusion protein increased the serum concentrations of anti-KLHIgG, total and of all subclasses, and anti-IgE (FIG. 23).

The in vivo studies in Example 8 and 9 show that MK61 polypeptideregulates immunity, with particular reference to adaptive immunity. Thedisruption of the interaction between MK61 and its as yet unknownligand(s) using a putatively ligand binding soluble form of the molecule(MK61-Fc fusion protein) results in lymphocyte expansion and Igproduction. This indicates that disrupting this interaction using“negative reagents” (such as MK61-Fc fusion protein, similarMK61-derived molecules or antagonistic antibodies directed against MK61or its ligand(s)) may lead to immunostimulation. While, artificiallycreating this interaction using “positive reagents” (such as MK61binding soluble forms of MK61 ligand(s), agonistic antibodies to MK61 orother molecules which activate the MK61 receptor) may lead toimmunosuppression.

1. An antibody or fragment thereof that specifically binds an MK61polypeptide produced by immunizing an animal with a polypeptidecomprising the amino acid sequence selected from the group consisting ofSEQ ID NO: 2, SEQ ID NO: 8, and SEQ ID NO:
 12. 2. An antibody orfragment thereof that specifically binds to a polypeptide comprising theamino acid sequence selected from the group consisting of SEQ ID NO: 2,SEQ ID NO: 8, and SEQ ID NO: 12, wherein the antibody or fragmentthereof binds to said amino acid sequence.
 3. An antibody or fragmentthereof that specifically binds to a polypeptide encoded by a nucleicacid sequence selected from the group consisting of: (a) a nucleotidesequence set forth in SEQ ID NO: 1; and (b) a nucleotide sequenceencoding the polypeptide as set forth in SEQ ID NO:
 2. 4. The antibodyof any one of claims 1-3 that is a human antibody or a fragment thereof.5. The antibody of any one of claims 1-3 that is a humanized antibody ora fragment thereof.
 6. The antibody of any one of claims 1-3 that is apolyclonal antibody or a fragment thereof.
 7. The antibody of any one ofclaims 1-3 that is a monoclonal antibody or a fragment thereof.
 8. Ahybridoma that produces the monoclonal antibody or the fragment thereofof claim
 7. 9. The antibody of any one of claims 1-3 which is achemically modified deriative.
 10. The derivative of claim 9 which iscovalently modified with a water-soluble polymer.
 11. The derivative ofclaim 10 wherein the water-soluble polymer is selected from the groupconsisting of polyethylene glycol, monomethoxy-polyethylene glycol,dextran, cellulose, poly-(N-vinyl pyrrolidone) polyethylene glycol,propylene glycol homopolymers, polypropylene oxide/ethylene oxideco-polymers, polyoxyethylated polyols, and polyvinyl alcohol.
 12. Theantibody of any one of claims 1-3, which is a Fab antibody.
 13. Theantibody of any one of claims 1-3, which is a Fab′ antibody.
 14. Theantibody of any one of claims 1-3 comprising a detectable label.
 15. Acomposition comprising the antibody of any one of claims 1-3 and apharmaceutically acceptable formulation agent.